# Girls Planet 999

Girls Planet 999 (Korean: 걸스플래닛999: 소녀대전) is a 2021 South Korean reality competition show created by Mnet. It premiered on August 6, 2021, and was originally broadcast every Friday at 8:20 PM KST for the first eleven episodes until its finale on October 22, which was broadcast live at 8 PM KST. It was aired on the Mnet channel, IQIYI, AbemaTV, tvN Asia, or YouTube depending on the viewer's region.
A production by Mnet's parent company CJ E&M and its subsidiary Studio Take One, as well as in collaboration with game developer and publisher NCSoft, the aim of the competition was to debut a new 9-member K-pop girl group consisting of trainees and idols from China, Japan, and South Korea. Auditions for the competition were held from January to February 2021.
Out of 13,000 applicants, 99 final contestants were selected. These 99 contestants were split equally into three groups; the K-Group, C-Group and the J-Group.
In the finale on October 22, 2021, which was broadcast live, the show announced the final 9 members who would debut as Kep1er.
A second season named Boys Planet featured an all male contestants premiered on February 2, 2023 featuring male trainees and idols.

## Concept and format

The "planet" theme of the show was derived from a new collaboration between Mnet and NCSoft's new platform called Universe which is centered around K-pop. It allowed votes from other countries outside of the participating three, and also hosted other promotional content for the show.
The show initially grouped the girls into groups of 3 which were called "cells." An entire cell of girls could be eliminated all at once, hence increasing the risk of elimination. To counteract this, the "Planet Top 9" is introduced. Contestants who are selected or voted to be the Planet Top 9 (designated P1 to P9) can reorganize cells to try and lower the chances of elimination. Cells were disbanded after the first elimination round. At the end of the competition, the top 9 most-voted contestants debuted regardless of nationality.

## Promotion and broadcast

The show, as well as its auditions, was first announced on January 11, 2021, through Mnet. Yeo Jin-goo was announced as the show's presenter on June 8, followed by the reveal of the mentors and the name of the show's opening theme later that same month. More promotional clips from the show were broadcast that month on Mnet.
The show's premiere date of August 6, 2021, was confirmed through a teaser video released on July 6, 2021. Another teaser video showcasing the faces of the 99 contestants was released on July 8, along with a promotional poster.
The theme song, "O.O.O (Over&Over&Over)," was released on July 12, 2021, accompanied by a performance by the Korean group with Kim Dayeon as Center. Another version of the performance featuring the Chinese group was released on July 14 with Shen Xiaoting as Center. The Japanese group's version was released on July 16 with Hikaru Ezaki as Center. The full version containing all three groups was released on July 29 during M Countdown, preceded by the contestants' profiles which were released from July 17 to 19 at 10 AM KST for each group. More teasers were released in July and August 2021 leading up to the show's premiere.
The show was available through Mnet in South Korea, iQIYI in China, AbemaTV and Mnet Japan in Japan, tvN Asia in Southeast Asia, and YouTube in the rest of the world through Mnet's YouTube channel, Mnet K-POP.

## Cast

The series was presented by Yeo Jin-goo, dubbed as the "Planet Master." The rest of the mentors, also dubbed as "masters," were:
* K-Pop Masters:
** Lee Sun-mi
** Tiffany Young
* Dance Masters:
** Baek Koo-young
** Jang Juhee
* Vocal Masters:
** Lim Han-byul
** Jo A-young
* Rap Master (Episodes 6–7):
** Woo Won-jae

## Contestants

There was a total of 99 contestants participating in the competition. 33 were Korean, and 33 consisted of Chinese, Taiwanese and Hongkongers, and the last 33 were Japanese.
The English names of K-Group and C-Group contestants are presented in Eastern order in accordance with the official website while J-Group contestants' names are presented in Western order.

### Color key (In order of contestant's group rank on the show)

99 contestants :
| K-Group (South Korea) |||||
| Kim Chae-hyun (김채현) | Huening Bahiyyih (휴닝바히에) | Choi Yu-jin (최유진) | Kim Da-yeon (김다연) | Seo Young-eun (서영은) |
| Kang Ye-seo (강예서) | Kim Su-yeon (김수연) | Guinn Myah (귄마야) | Kim Bo-ra (김보라) | Kim Do-ah (김도아) |
| Yoon Ji-a (윤지아) | Jeong Ji-yoon (정지윤) | An Jeong-min (안정민) | Lee Hye-won (이혜원) | Kim Hye-rim (김혜림) |
| Huh Ji-won (허지원) | Choi Ye-young (최예영) | Lee Chae-yun (이채윤) | You Da-yeon (유다연) | Kim Se-in (김세인) |
| Sim Seung-eun (심승은) | Lee Yeon-gyung (이연경) | Lee Ra-yeon (이나연) | Lee Sun-woo (이선우) | Kim Ye-eun (김예은) |
| Lee Yun-ji (이윤지) | Choi Hye-rin (최혜린) | Ryu Si-on (류시온) | Suh Ji-min (서지민) | Joung Min (정민) |
| Kim Yu-bin (김유빈) | Cho Ha-eun (조하은) | Han Da-na (한다나) | | |
| C-Group (China, Taiwan, Hong Kong) |||||
| Shen Xiaoting (沈小婷) | Fu Yaning (符雅凝) | Su Ruiqi (苏芮琪) | Wen Zhe (文哲) | Huang Xingqiao (黄星侨) |
| Chen Hsinwei (陳昕葳) | Zhou Xinyu (周心语) | Cai Bing (蔡冰) | Xu Ziyin (徐紫茵) | Liang Jiao (梁娇) |
| Li Yiman (李伊蔓) | Yang Zige (杨梓格) | Wang Yale (王雅乐) | Zhang Luofei (张洛菲) | Hsu Nientzu (許念慈) |
| Chiayi (家儀) | Wu Tammy (吴甜蜜) | Leung Cheukying (梁卓瀅) | Xia Yan (夏研) | Liang Qiao (梁乔) |
| Xu Ruowei (徐若惟) | Gu Yizhou (顾逸舟) | Chang Ching (張競) | Ma Yuling (马玉灵) | Lin Chenhan (林辰涵) |
| Cui Wenmeixiu (崔文美秀) | Chien Tzuling (簡紫翎) | Ho Szeching (何思澄) | Poon Wingchi (潘穎芝) | Lin Shuyun (林書蘊) |
| Liu Shiqi (刘诗琦) | Wang Qiuru (王秋茹) | Liu Yuhan (刘钰涵) | | |
| J-Group (Japan) |||||
| Hikaru Ezaki (江崎ひかる) | Mashiro Sakamoto (坂本舞白) | Yurina Kawaguchi (川口ゆりな) | Shana Nonaka (野仲紗奈) | Ruan Ikema (池間琉杏) |
| Manami Nagai (永井愛実) | Ririka Kishida (岸田莉里花) | May (メイ) | Kotone Kamimoto (嘉味元琴音) | Reina Kubo (久保玲奈) |
| Miu Sakurai (櫻井美羽) | Ayana Kuwahara (桑原彩菜) | Moana Yamauchi (山内若杏名) | Shihona Sakamoto (坂本志穂菜) | Risako Arai (新井理沙子) |
| Moka Shima (島望叶) | Ayaka Fujimoto (藤本彩花) | Hana Hayase (早瀬華) | Miyu Ito (伊藤美優) | Fuko Hayashi (林楓子) |
| Nagomi Hiyajo (比屋定和) | Rinka Ando (安藤梨花) | Rinka Aratake (荒武凛香) | Momoko Okazaki (岡崎百々子) | Vivienne Inaba (稲葉ヴィヴィアン) |
| Yume Murakami (村上結愛) | Rei Kamikura (神藏令) | Hina Terasaki (寺崎日菜) | Sumomo Okuma (大熊李) | Fuka Oki (沖楓花) |
| Miyu Kanno (菅野美優) | Yuna Kitajima (北島由菜) | Kyara Nakamura (中村伽羅) | | |

## Ranking
### Planet Top 9

The Planet Top 9 was either selected by the mentors (Episode 2) or voted by viewers of the show; those selected to be the Planet Top 9 in Episode 2 were given the ability to reshuffle and organize cells.
Color key:
| # | Ep. 2 | Ep. 5 | Ep. 8 | Ep. 9 | Ep. 11 | Special Live | Ep. 12 |
| # | Contestant | Contestant | Contestant | Contestant | Contestant | Contestant | Contestant |
| P1 | Hikaru Ezaki | Yurina Kawaguchi | Shen Xiaoting (1) | Shen Xiaoting | Shen Xiaoting | Kim Chaehyun (10) | Kim Chaehyun |
| P2 | Kang Yeseo | Shen Xiaoting (1) | Yurina Kawaguchi (1) | Kim Dayeon (8) | Kim Dayeon | Choi Yujin (3) | Huening Bahiyyih (3) |
| P3 | Shen Xiaoting | Hikaru Ezaki (2) | Mashiro Sakamoto (2) | Hikaru Ezaki (1) | Mashiro Sakamoto (1) | Kim Dayeon (1) | Choi Yujin (1) |
| P4 | Su Ruiqi | Choi Yujin (3) | Hikaru Ezaki (1) | Mashiro Sakamoto (1) | Hikaru Ezaki (1) | Seo Youngeun (5) | Kim Dayeon (1) |
| P5 | Jeong Jiyoon | Mashiro Sakamoto | Choi Yujin(1) | Yurina Kawaguchi (3) | Choi Yujin (1) | Huening Bahiyyih (8) | Seo Youngeun (1) |
| P6 | Seo Youngeun | Su Ruiqi (2) | Su Ruiqi | Choi Yujin (1) | Yurina Kawaguchi (1) | Kang Yeseo (6) | Kang Yeseo |
| P7 | Choi Yujin | Cai Bing (1) | Huang Xingqiao | Su Ruiqi (1) | Shana Nonaka (2) | Kim Suyeon (10) | Hikaru Ezaki (5) |
| P8 | Cai Bing | Kang Yeseo (6) | Cai Bing (1) | Kim Chaehyun (1) | Fu Yaning (2) | Guinn Myah (17) | Mashiro Sakamoto (6) |
| P9 | Ayana Kuwahara | Kim Chaehyun | Kim Chaehyun | Shana Nonaka (2) | Seo Youngeun (3) | Su Ruiqi (1) | Shen Xiaoting (7) |

### Planet Pass

Planet Pass was a vote by the mentors, in which eliminated contestants could be brought back to the show.
The first two elimination rounds included a Planet Pass for one eliminated contestant from each group. The third elimination round included only one Planet Pass which could go to any eliminated contestant regardless of group.
| Ep. 5 | Ep. 8 | Ep. 11 |
| Ruan Ikema | Kotone Kamimoto | Guinn Myah |
| Wen Zhe | Zhou Xinyu | Guinn Myah |
| Kim Hyerim | Kim Suyeon | Guinn Myah |

### First voting period

The first voting period took place from August 13, 2021, to August 28, 2021.
Voters (viewers and mentors) voted for three cells, as well as three girls of each group.
Eliminations were based on cell points, while the Planet Top 9 was based on individual points.
Color key:
Cell Rank :
| Rank | Episode 3 | Episode 3 | Episode 3 | Episode 3 | Episode 5 | Episode 5 | Episode 5 | Episode 5 |
| Rank | Cell Members | Cell Members | Cell Members | Points | Cell Members | Cell Members | Cell Members | Points |
| Rank | K | C | J | Points | K | C | J | Points |
| 1 | Choi Yujin | Cai Bing | May | 1,328,882 | Choi Yujin | Cai Bing | May | 2,929,629 |
| 2 | Seo Youngeun | Shen Xiaoting | Yurina Kawaguchi | 1,176,035 | Seo Youngeun | Shen Xiaoting | Yurina Kawaguchi | 2,649,735 |
| 3 | Jeong Jiyoon | Su Ruiqi | Hikaru Ezaki | 1,065,592 | Jeong Jiyoon | Su Ruiqi | Hikaru Ezaki | 2,048,599 |
| 4 | Kang Yeseo | Huang Xingqiao | Mashiro Sakamoto | 843,274 | Kang Yeseo | Huang Xingqiao | Mashiro Sakamoto | 1,912,854 |
| 5 | Huening Bahiyyih | Hsu Nientzu | Shihona Sakamoto | 534,755 | Kim Chaehyun | Li Yiman | Ayana Kuwahara | 1,153,957 |
| 6 | Kim Doah | Xu Ziyin | Risako Arai | 502,682 | Kim Doah | Xu Ziyin | Risako Arai | 1,134,128 |
| 7 | Kim Chaehyun | Li Yiman | Ayana Kuwahara | 351,067 | Huening Bahiyyih | Hsu Nientzu | Shihona Sakamoto | 1,025,869 |
| 8 | Kim Suyeon | Fu Yaning | Shana Nonaka | 286,390 | Kim Suyeon | Fu Yaning | Shana Nonaka | 640,747 |
| 9 | Kim Dayeon | Wu Tammy | Miu Sakurai | 223,105 | Kim Dayeon | Wu Tammy | Miu Sakurai | 589,272 |
| 10 | Choi Yeyoung | Chen Hsinwei | Reina Kubo | 209,637 | Choi Yeyoung | Chen Hsinwei | Kubo Reina | 490,970 |
| 11 | Lee Chaeyun | Leung Cheukying | Ririka Kishida | 183,342 | Guinn Myah | Yang Zige | Kotone Kamimoto | 485,596 |
| 12 | An Jeongmin | Wang Yale | Ayaka Fujimoto | 156,942 | Huh Jiwon | Chiayi | Moana Yamauchi | 467,491 |
| 13 | Huh Jiwon | Chiayi | Moana Yamauchi | 156,595 | Lee Chaeyun | Leung Cheukying | Ririka Kishida | 431,400 |
| 14 | Lee Hyewon | Liang Jiao | Manami Nagai | 148,979 | Lee Hyewon | Liang Jiao | Manami Nagai | 419,671 |
| 15 | You Dayeon | Xu Ruowei | Rei Kamikura | 122,428 | An Jeongmin | Wang Yale | Ayaka Fujimoto | 392,201 |
| 16 | Guinn Myah | Yang Zige | Kotone Kamimoto | 117,496 | Kim Bora | Zhang Luofei | Hana Hayase | 383,678 |
| 17 | Kim Sein | Wen Zhe | Momoko Okazaki | 110,687 | Yoon Jia | Zhou Xinyu | Moka Shima | 370,017 |
| – | — | — | — | — | Kim Hyerim | Wen Zhe | Ruan Ikema | Planet Pass |
Results from 1st Global vote where viewers chose 3 contestants each vote. Benefits are included.
Episode 5 - Planet Top 9 :
| # | Name | Points | Points | Points | Group |
| # | Name | Total | Korean | Global | Group |
| P1 | Kawaguchi Yurina | 4,446,387 | 342,119 | 1,816,746 | J |
| P2 | Shen Xiaoting | 3,919,277 | 298,212 | 1,620,685 | C |
| P3 | Hikaru Ezaki | 3,138,429 | 208,676 | 1,471,455 | J |
| P4 | Choi Yujin | 3,119,661 | 218,207 | 1,400,513 | K |
| P5 | Sakamoto Mashiro | 2,784,657 | 180,474 | 1,322,567 | J |
| P6 | Su Ruiqi | 2,598,795 | 124,836 | 1,494,945 | C |
| P7 | Cai Bing | 2,361,224 | 168,887 | 1,038,526 | C |
| P8 | Kang Yeseo | 1,744,198 | 128,658 | 744,635 | K |
| P9 | Kim Chaehyun | 1,704,528 | 142,258 | 632,422 | K |

### Second voting period

The second voting period took place from September 3, 2021, to September 18, 2021.
Voters voted for three contestants of each group.
Eliminations were based on individual points within K-Group, C-Group and J-Group.
Color key:
Surviving Contestants (by group) :
| Rank | Episode 8 | Episode 8 | Episode 8 | Episode 8 | Episode 8 | Episode 8 |
| Rank | K | K | C | C | J | J |
| Rank | Name | Points | Name | Points | Name | Points |
| 1 | Choi Yujin (–) | 3,173,040 | Shen Xiaoting (–) | 5,517,873 | Yurina Kawaguchi (–) | 4,661,720 |
| 2 | Kim Chaehyun (↑1) | 2,665,915 | Su Ruiqi (–) | 2,912,831 | Mashiro Sakamoto (↑1) | 4,578,784 |
| 3 | Kim Dayeon (↑4) | 2,614,923 | Huang Xingqiao (↑1) | 2,816,654 | Hikaru Ezaki (↓1) | 4,176,316 |
| 4 | Kang Yeseo (↓2) | 2,475,538 | Cai Bing (↓1) | 2,682,114 | Shana Nonaka (↑2) | 2,563,703 |
| 5 | Seo Youngeun (↓1) | 2,015,176 | Wen Zhe (↑6) | 2,197,276 | Manami Nagai (↑2) | 2,363,513 |
| 6 | Guinn Myah (↑3) | 1,803,320 | Chen Hsinwei (↓1) | 1,751,753 | Ririka Kishida (↓1) | 2,221,061 |
| 7 | Kim Bora (↑5) | 1,662,629 | Fu Yaning (–) | 1,658,939 | Ruan Ikema (↑7) | 1,729,825 |
| 8 | Huening Bahiyyih (↓2) | 1,503,092 | Xu Ziyin (↓2) | 1,637,433 | May (↓4) | 1,696,554 |
| – | Kim Suyeon | Planet Pass | Zhou Xinyu | Planet Pass | Kotone Kamimoto | Planet Pass |
Planet Rank (Surviving Contestants) :
| Episode 8 |||||||||
| # | Name | Points | # | Name | Points | # | Name | Points |
| P1 | Shen Xiaoting | 5,517,873 | P10 | Kim Dayeon | 2,614,923 | P19 | Ruan Ikema | 1,729,825 |
| P2 | Yurina Kawaguchi | 4,661,720 | P11 | Shana Nonaka | 2,563,703 | P20 | May | 1,696,554 |
| P3 | Mashiro Sakamoto | 4,578,784 | P12 | Kang Yeseo | 2,475,538 | P21 | Kim Bora | 1,662,629 |
| P4 | Hikaru Ezaki | 4,176,316 | P13 | Manami Nagai | 2,363,513 | P22 | Fu Yaning | 1,658,939 |
| P5 | Choi Yujin | 3,173,040 | P14 | Ririka Kishida | 2,221,061 | P23 | Xu Ziyin | 1,637,433 |
| P6 | Su Ruiqi | 2,912,831 | P15 | Wen Zhe | 2,197,276 | P24 | Huening Bahiyyih | 1,503,092 |
| P7 | Huang Xingqiao | 2,816,654 | P16 | Seo Youngeun | 2,015,176 | – | Kotone Kamimoto | Planet Pass |
| P8 | Cai Bing | 2,682,114 | P17 | Guinn Myah | 1,803,320 | – | Zhou Xinyu | Planet Pass |
| P9 | Kim Chaehyun | 2,665,915 | P18 | Chen Hsinwei | 1,751,753 | – | Kim Suyeon | Planet Pass |

### Third voting period

The third voting period took place from September 24, 2021, to October 9, 2021. Voters could only vote for one contestant from each group.
Eliminations were based on individual votes regardless of group.
Planet Rank (Surviving Contestants) :
| Episode 9 | Episode 9 | Episode 9 | Episode 9 | Episode 11 | Episode 11 | Episode 11 | Episode 11 | Episode 11 | Episode 11 |
| # | Name | # | Name | # | Name | Points | # | Name | Points |
| P1 | Shen Xiaoting (–) | P10 | Fu Yaning (↑12) | P1 | Shen Xiaoting (–) | 4,161,699 | P10 | Su Ruiqi (↓3) | 1,369,169 |
| P2 | Kim Dayeon (↑8) | P11 | Kang Yeseo (↑1) | P2 | Kim Dayeon (–) | 2,395,726 | P11 | Kim Chaehyun (↓3) | 1,308,669 |
| P3 | Hikaru Ezaki (↑1) | P12 | Seo Youngeun (↑4) | P3 | Mashiro Sakamoto (↑1) | 2,314,788 | P12 | Kang Yeseo (↓1) | 1,248,877 |
| P4 | Mashiro Sakamoto (↓1) | P13 | Huening Bahiyyih (↑11) | P4 | Hikaru Ezaki (↓1) | 2,185,083 | P13 | Huening Bahiyyih (–) | 1,238,862 |
| P5 | Yurina Kawaguchi (↓3) | P14 | Wen Zhe (↑1) | P5 | Choi Yujin (↑1) | 1,747,716 | P14 | Wen Zhe (–) | 1,121,791 |
| P6 | Choi Yujin (↓1) | P15 | Huang Xingqiao (↓8) | P6 | Yurina Kawaguchi (↓1) | 1,692,862 | P15 | Kim Bora (↑6) | 1,023,271 |
| P7 | Su Ruiqi (↓1) | P16 | Ruan Ikema (↑3) | P7 | Shana Nonaka (↑2) | 1,621,602 | P16 | Huang Xingqiao (↓1) | 1,015,623 |
| P8 | Kim Chaehyun (↑1) | P17 | Manami Nagai (↓4) | P8 | Fu Yaning (↑2) | 1,548,272 | P17 | Kim Suyeon (↑3) | 989,381 |
| P9 | Shana Nonaka (↑2) | P18 | Chen Hsinwei (–) | P9 | Seo Youngeun (↑3) | 1,524,572 | – | Guinn Myah | Planet Pass |

### Fourth voting period

The first round of the fourth voting period took from October 15, 2021, until 10AM KST on October 22, 2021.
The second round was open during the finale live broadcast on October 22, 2021; all live votes were doubled.
Voters could only vote for one contestant out of the eighteen remaining.
The members of the debut lineup were decided based on individual votes regardless of group.
Planet Rank :
| <9IRLS NI9HT A9IT> Special Live | <9IRLS NI9HT A9IT> Special Live | <9IRLS NI9HT A9IT> Special Live | <9IRLS NI9HT A9IT> Special Live | Episode 12 | Episode 12 | Episode 12 | Episode 12 | Episode 12 | Episode 12 |
| # | Name | # | Name | # | Name | Points | # | Name | Points |
| P1 | Kim Chaehyun (↑10) | P10 | Fu Yaning (↓2) | P1 | Kim Chaehyun (–) | 1,081,182 | P10 | Kim Suyeon (↓3) | 650,790 |
| P2 | Choi Yujin (↑3) | P11 | Kim Bora (↑4) | P2 | Huening Bahiyyih (↑3) | 923,567 | P11 | Guinn Myah (↓3) | 625,722 |
| P3 | Kim Dayeon (↓1) | P12 | Hikaru Ezaki (↓8) | P3 | Choi Yujin (↓1) | 915,722 | P12 | Fu Yaning (↓2) | 560,606 |
| P4 | Seo Youngeun (↑5) | P13 | Yurina Kawaguchi (↓7) | P4 | Kim Dayeon (↓1) | 885,286 | P13 | Su Ruiqi (↓4) | 552,878 |
| P5 | Huening Bahiyyih (↑8) | P14 | Mashiro Sakamoto (↓11) | P5 | Seo Youngeun (↓1) | 781,657 | P14 | Yurina Kawaguchi (↓1) | 525,051 |
| P6 | Kang Yeseo (↑6) | P15 | Shana Nonaka (↓8) | P6 | Kang Yeseo (–) | 770,561 | P15 | Kim Bora (↓4) | 503,773 |
| P7 | Kim Suyeon (↑10) | P16 | Shen Xiaoting (↓15) | P7 | Hikaru Ezaki (↑5) | 713,322 | P16 | Shana Nonaka (↓1) | 342,370 |
| P8 | Guinn Myah (↑17) | P17 | Wen Zhe (↓3) | P8 | Mashiro Sakamoto (↑6) | 708,149 | P17 | Wen Zhe (–) | 88,673 |
| P9 | Su Ruiqi (↑1) | P18 | Huang Xingqiao (↓2) | P9 | Shen Xiaoting (↑7) | 700,663 | P18 | Huang Xingqiao (–) | 56,600 |

### Result

The finale was held and broadcast live on October 22, 2021. Yeo Jin-goo announced the newly formed girl group name to be Kep1er (케플러).
Episode 12 :
| # | Name | Points | Company |
| P1 | Kim Chaehyun | 1,081,182 | Wake One Entertainment |
| P2 | Huening Bahiyyih | 923,567 | IST Entertainment |
| P3 | Choi Yujin | 915,722 | Cube Entertainment |
| P4 | Kim Dayeon | 885,286 | Jellyfish Entertainment |
| P5 | Seo Youngeun | 781,657 | Biscuit Entertainment |
| P6 | Kang Yeseo | 770,561 | 143 Entertainment |
| P7 | Hikaru Ezaki | 713,322 | Avex Artist Academy |
| P8 | Mashiro Sakamoto | 708,149 | 143 Entertainment |
| P9 | Shen Xiaoting | 700,663 | Top Class Entertainment |

## Episodes

| No. | Title | Original release date |
| 1 | "Contact (너와 내 꿈들이 연결될 시간)" | August 6, 2021 (2021-08-06) |
| The episode opens with all 99 girls being divided into cells, each consisting of a Korean, Chinese, and Japanese contestant. Groupings are based on a variety of characteristics common to the girls, such as type of career and personal interests. The competition's host Yeo Jin-goo and mentors are introduced. Yeo then explains the rules of the competition, revealing that a cell of girls can all be eliminated at once; he also explains that if a girl lands a spot in the "Planet Top 9", they will be given the option to rearrange cells. Each girl is evaluated to determine whether they should be considered to become a Planet Top 9 candidate and their initial ranking is revealed prior to each performance based on the theme song evaluation test. |||
| 2 | "Contact (너의 세계가 궁금해)" | August 13, 2021 (2021-08-13) |
| Evaluations continue, and the Planet Top 9 for the episode are announced; the top three contestants consisted of Hikaru Ezaki (J-Group), Kang Yeseo (K-Group) and Shen Xiaoting (C-Group). The cells are then either rearranged or kept. The next day, the girls participate in a mission where they have to connect with their childhood photos. The fastest teams are given priority to form teams for the first mission, dubbed as the "Connect Mission". There are two categories in the Connect Mission round. The main category consisted of four girl group songs (Blackpink - How You Like That, Iz*One - Fiesta, Twice - Yes or Yes, Oh My Girl - The Fifth Season (SSFWL)). The four winning teams will have their vote count doubled 24 hours before voting concludes. The second category is known as EBS (Exo - The Eve, BTS - Mic Drop, and Seventeen - Pretty U). Only one team can win in this category but their vote count will be tripled 24 hours before voting concludes. Each team consisted of three cells each, with nine members per team and eleven teams overall. The best out of the five winning performances will perform on M Countdown after the mission. |||
| 3 | "Connect (너도 내 우주에 끌리고 있잖아)" | August 20, 2021 (2021-08-20) |
| Current cell rankings are displayed at the beginning of the episode. Contestants begin preparing for their first mission by determining their positions in the performance. Several days before the team performances, a dance battle is held to determine the order in which the teams will perform. Following the dance competition, the teams continue to practice, with the mentors offering feedback on how to improve. The group performances then begin. "Yes or Yes" Team 1 wins, followed by "How You Like That" Team 1. The episode ends with the "Eve" team about to perform. |||
| 4 | "Connect (더 확실하게 My Sign)" | August 27, 2021 (2021-08-27) |
| The group performances continue. "Fiesta" Team 1 wins, followed by "The Fifth Season" Team 1. The boy group song performances are then shown, with the "Pretty U" team securing the most points out of the three and winning. After the completion of the performances, the winning team that will get to perform on M Countdown is revealed to be "Yes or Yes" Team 1. During the end credits, it is revealed that only 54 contestants will survive in the following episode, meaning that 45 contestants will be eliminated. |||
| 5 | "It's Me! (바로 나야!)" | September 3, 2021 (2021-09-03) |
| The first ranking announcement begins. The top 16 cells are first announced, with the cell of Choi Yujin, Cai Bing and May securing first place with 2,929,629 points. For the last surviving cell, the cell of Yoon Jia, Zhou Xinyu and Moka Shima remains in the competition as the surviving cell. Then, the results of the Planet Pass is announced; the Planet Pass is a vote between the mentors in which eliminated contestants would be given a chance to continue in the competition. K-Group's Kim Hyerim, C-Group's Wen Zhe and J-Group's Ruan Ikema are announced to be receiving the Planet Pass, allowing them to remain in the competition. Following this, the new Planet Top 9 are then announced, with J-Group's Yurina Kawaguchi obtaining first place with 4,446,387 points. During the preview of the next episode, it is revealed that the next round dubbed as the "Combination Mission" will begin in the following episode. |||
| 6 | "Combination (더 확실하게 My Sign)" | September 10, 2021 (2021-09-10) |
| Host Yeo Jin-goo explains to the girls that the next mission would be the Combination Mission, revealing that the cell system would be phased out leading to all rankings being individual. He then explains the Combination Mission, stating that the 54 girls will be split into either 3-member, 6-member or 9-member teams for the mission. There are a total of six songs for 3-member teams, three songs for 6-member teams and two songs for 9-member teams. The girls form their teams, with priority given to the first round's top placing cell. While preparing, the girls are evaluated by the mentors through an interim check. The performances begin, with the "We Are" team performing first. The episode ends with the "Fate" team about to perform. Four songs created for the next mission dubbed as the "Creation Mission" are also revealed. Viewers ae told to vote who they wanted to perform which song through the Universe app. |||
| 7 | "같은 꿈을 꾸는 너와 나" | September 17, 2021 (2021-09-17) |
| The Combination Mission performances continue. The winners of the Combination Mission are then announced. For the 3-person teams, the "In the Morning" team wins, securing 90,000 points each. For the 6-person teams, the "Fate" team wins, securing 45,000 points each. For the 9-person teams, the "Salute" team wins, securing 30,000 points each. During the previews for the next episode, the girls are introduced to the Creation Mission songs which were previously shown to the audience in the previous episode. It is also reiterated that 27 girls will be eliminated next episode, along with the continued implementation of the Planet Pass. |||
| 8 | "생존자 발표식 (손을 잡아줘)" | September 24, 2021 (2021-09-24) |
| The 54 girls split into four different groups for the four Creation Mission songs, having been arranged through viewer's votes. The girls begin trying to arrange themselves in their assigned songs. In the midst of rehearsals, the second elimination round results are announced to the girls. The top seven contestants in each group are revealed, followed by the eighth-ranking contestant of each group. Following this, the new Planet Top 9 is announced. C-Group's Shen Xiaoting achieves first place with 5,517,873 points. Shortly after, the Planet Pass recipients are announced. They are announced to be K-Group's Kim Suyeon, C-Group's Zhou Xinyu, and J-Group's Kotone Kamimoto. At the end of the episode, it is also revealed that Xu Ziyin, who placed 8th in C-Group, has left the show due to health issues. |||
| 9 | "Creation #1 (신곡) (I'm gonna be your star)" | October 1, 2021 (2021-10-01) |
| The Creation Mission continues with the 26 girls rearranging parts and changing lineups for their Creation Mission songs. Due to the eliminations, some teams has excess or are short of a few members. Only the "Shoot!" team does not require any changes. During the preparation period, the four teams embark on a special mission entitled the Planet Teamwork Mission. In the Planet Teamwork Mission, all teams must perform their Creation Mission songs no matter where they go using teamwork. The four teams have to pick any of the four waiting buses which will ferry them to their destination. The "Shoot!" team goes to meets the mother of K-Group's Kim Dayeon. The "Snake" team visits a rural town, harvesting sweet potatoes and chili peppers. The "U+Me=LOVE" team goes to Lotte World Tower and receives a massage and a dinner at a luxurious restaurant. The "Utopia" team hikes to a paragliding ground and paraglides with the assistance of instructors. Each team performs their song at the location they visited. Afterwards, the teams continue to prepare for the Creation Mission. They are interrupted when the second interim results are announced to the girls. The top 18 contestants are announced in ascending order, followed by the current Planet Top 9. The top three are announced to be C-Group's Shen Xiaoting, K-Group's Kim Dayeon and J-Group's Hikaru Ezaki. They also place first in their respective groups. After the second interim results, footage from a month earlier shows the 54 girls from the Combination Mission embarking on a field day. The girls from each group form a team and compete in a series of games. The winning team receives fleece jackets while the runner-up team receives cosmetics sets. The J-Group won with a total of 720 points, followed by the C-Group with 450 points and the K-Group with 300 points. The episode ends with the K-Group receiving towels as a prize for finishing 3rd. |||
| 10 | "한 걸음 한 걸음 좀 더 가까이" | October 8, 2021 (2021-10-08) |
| The episode begins with the girls attending a fan meeting with some viewers of the show. They perform several of their past performances from the Planet Demo Stage and the previous two missions. After the fan meeting, the girls give presents to the audience. The episode then begins with the commencement of the Creation Mission performances. The "Shoot!" team performs first, followed by the "Utopia" team. The "U+Me=LOVE" team then performs, followed by the "Snake" team. After the performances, the winner is announced to be the "U+Me=LOVE" team, scoring 94.17 out of 100 points. Then, it is revealed that another mission named the O.O.O Mission will take place during the next episode. Further details are revealed; the girls will be first organized into 3 different groups that will perform a debut group version of the show's theme song, "O.O.O (Over&Over&Over)". The teams were voted for by the viewers through Universe. |||
| 11 | "생존자 발표식 (응답해줘 오버)" | October 15, 2021 (2021-10-15) |
| The episode begins with the O.O.O Mission. The girls are grouped into three different teams; two containing nine members and the third containing eight. In between performances, the girls are shown video messages and performances by viewers of the show from around the world. The winners of the O.O.O Mission were determined by the viewers of the show; the contestant of each team that accumulated the most number of YouTube likes on their respective video within 24 hours would obtain a benefit of 90,000 (nine-member) or 80,000 points (eight-member). The winners of the O.O.O mission are announced to be Choi Yujin (Team 1) and Huening Bahiyyih (Team 2), each obtaining the 90,000 points, as well as Seo Youngeun (Team 3) who obtains 80,000 points. The episode then proceeds to the third ranking elimination. C-Group's Shen Xiaoting maintains her first place ranking with 4,161,699 points. After the seventeen survivors are announced, the Planet Pass recipient is then revealed to be K-Group's Guinn Myah. The episode ends with the preview of the final episode's mission called the Completion Mission. |||
| 12 | "파이널 생방송 (손을 잡아줘)" | October 22, 2021 (2021-10-22) |
| The 18 finalists perform the show's theme song. Host Yeo Jin-goo then announces the opening of the final voting round where all live votes are doubled. The finalists' audition and highlight videos are then shown. Yeo explains the live voting process, stating that the final count is a sum of the votes from the first week and the votes during the live finale. He then interacts with members from a live Zoom audience as well as the mentors and some eliminated contestants that constitute the live audience. The current 9th place candidates are announced, revealed to be C-Group's Shen Xiaoting and J-Group's Hikaru Ezaki. The episode cuts to the day where the finalists are introduced to the Completion Mission song "Shine". The finalists form two teams of nine that will perform the song together during the finale. Yeo then reveals the debuting girl group's name to be Kep1er, followed by a performance of "Shine" by the finalists. The episode then cuts to a week prior where the finalists watch videos recorded by themselves and fellow contestants after the first mission. The finalists then perform "Another Dream", a pop ballad song. The episode again cuts to a night where the finalists are treated to a party, reviewing self-created artworks, receiving a lavish dinner, viewing polaroids that serve as memories and watching videos recorded by some of their parents. Yeo begins to announce the debut lineup of Kep1er. J-Group's Mashiro Sakamoto and Hikaru Ezaki place 8th and 7th respectively. K-Group's Kang Yeseo, Seo Youngeun, Kim Dayeon, Choi Yujin, Huening Bahiyyih and Kim Chaehyun place subsequently in ascending order. The 9th place candidates are revealed to be C-Group's Shen Xiaoting, as well as K-Group's Kim Suyeon and Guinn Myah. The 9th ranker is announced to be C-Group's Shen Xiaoting. The episode comes to a close with the debuting and eliminated girls coming together, congratulating each other and exchanging hugs. |||

## Discography
### Extended plays

| Title | Details | Peak chart positions |
| Title | Details | JPN Hot |
| Girls Planet 999 – Creation Mission | Released: October 8, 2021 Label: Stone Music Entertainment Formats: Digital download, streaming Track list U+Me=LOVE Snake (뱀) Shoot! Utopia | 11 |
| Girls Planet 999 – Completion Mission | Released: October 22, 2021 Label: Stone Music Entertainment Formats: Digital download, streaming Track list Shine Another Dream | — |
| "—" denotes releases that did not chart or were not released in that territory. |||

### Singles

| Title | Year | Peak chart positions | Album |
| Title | Year | KOR DL | Album |
| "O.O.O (Over&Over&Over)" | 2021 | — | Non-album single |
| "U+Me=LOVE" | 2021 | 125 | Girls Planet 999 – Creation Mission |
| "Snake" (뱀) | 2021 | 145 | Girls Planet 999 – Creation Mission |
| "Shoot! " | 2021 | 139 | Girls Planet 999 – Creation Mission |
| "Utopia" | 2021 | 121 | Girls Planet 999 – Creation Mission |
| "Shine" | 2021 | 157 | Girls Planet 999 – Completion Mission |
| "Another Dream" | 2021 | — | Girls Planet 999 – Completion Mission |
| "—" denotes releases that did not chart or were not released in that territory. ||||

## Ratings

Average TV viewership ratings :
| Ep. | Original broadcast date | Average audience share |
| Ep. | Original broadcast date | Nationwide |
| 1 | August 6, 2021 | 0.461% (77th) |
| 2 | August 13, 2021 | 0.760% (43rd) |
| 3 | August 20, 2021 | 0.708% (47th) |
| 4 | August 27, 2021 | 0.711% (47th) |
| 5 | September 3, 2021 | 0.858% (31st) |
| 6 | September 10, 2021 | 0.787% (39th) |
| 7 | September 17, 2021 | 0.838% (42nd) |
| 8 | September 24, 2021 | 0.793% (38th) |
| 9 | October 1, 2021 | 0.710% (41st) |
| 10 | October 8, 2021 | 0.592% (55th) |
| 11 | October 15, 2021 | 0.634% (49th) |
| 12 | October 22, 2021 | 0.889% (34th) |
| Average | Average | 0.728% |
| In the table below, blue numbers represent the lowest ratings and red numbers represent the highest ratings. This show aired on a cable channel/pay TV which normally has a relatively smaller audience compared to free-to-air TV/public broadcasters (KBS, SBS, MBC and EBS). |||

## Aftermath

Kep1er was supposed to debut on December 14, 2021, with the mini album First Impact, but due to one of their staff members testing positive for COVID-19, their debut was delayed to January 3, 2022. The group's debut performance at the 2021 Mnet Asian Music Awards on December 11 was also cancelled as a result, as well as some members testing positive for COVID-19. The group officially debuted on January 3, 2022. Since then, they have released two studio albums (one in Korean and one in Japanese), five EPs and three Japanese singles. In May 2024, it was revealed that all members, except for Sakamoto Mashiro and Kang Ye-seo, renewed their contracts with WakeOne.
* Mashiro and Yeseo left Kep1er on July 15, 2024, after the group's concerts in Yokohama, Japan. They debuted in 143 Entertainment's girl group Madein on September 3, 2024, with their first mini album, Rise.
* Some contestants returned to their original groups:
** Ma Yuling (C24) and Wang Qiuru (C32) returned to SNH48.
** Liang Jiao (C10) and Liang Qiao (C20) returned to GNZ48.
** Su Ruiqi (P13) returned to Chic Chili.
** Wen Zhe (P17) returned to Hickey.
** Sim Seungeun (K21) returned to Bvndit and joined group promotions for their third mini album, Re-Original, in May 2022. Bvndit disbanded on November 11, 2022, after all the members terminated all their contracts with MNH.
** Lee Rayeon (K23), Chiayi (C16) and Kim Doah (K10) returned to Fanatics. The group disbanded sometimes in 2024.
** Huh Jiwon (K16), May (P23) and Kim Bora (P15) returned to Cherry Bullet and rejoined group promotions for their second mini album, Cherry Wish, in March 2022. Cherry Bullet disbanded on April 22, 2024, after several members, including Jiwon and May, terminated their exclusive contracts.
* Some trainees left their agencies/joined new agencies:
** Chang Ching (C23) and Lee Yunji (K26) left Yuehua Entertainment and Cube Entertainment respectively. Later, they signed with FC ENM, the same agency of contestants Ririka Kishida (P22) and Hana Hayase (J18).
** Ruan Ikema (P19) and Hina Terasaki (J28) signed with KISS Entertainment.
** Jeong Jiyoon (K12) signed with KM Entertainment.
** You Dayeon (K19) left Highline Entertainment.
** Han Dana (K33) signed a contract with Beats Entertainment.
** Miyu Ito (J19) signed a contract with 143 Entertainment, the company that manages Kep1er members Kang Yeseo (P6) and Mashiro Sakamoto (P8).
** Li Yiman (C11) signed a contract with FLEX M.
** Shihona Sakamoto (J14) left Jellyfish Entertainment.
** Kim Yeeun (K25) left Fantagio Music.
** Choi Hyerin (K27) left MNH Entertainment.
** Chien Tzuling (C27) left Yuehua Entertainment.
** Kim Hyerim (K15) signed with Doubling Music.
** Xia Yan (C19) joined Real Show Culture Company.
** Lee Yeongyung (K22) joined Come & Funny Corporation.
** Risako Arai (J15) and Yume Murakami (J24) left Biscuit Entertainment. Then, Risako signed with iME Korea
** Kotone Kamimoto (P24) joined Modhaus.
** An Jeongmin (K13) left TOP Media.
** Sim Seungeun left MNH Entertainment.
** Hsu Nientzu (C15) left FNC Entertainment & joined Modhaus.
** SNH48's Wang Qiuru (C32) graduated on April 4, 2023.
** Zhou Xinyu (P22) left Yuehua Entertainment & joined Modhaus.
** Joung Min (K30) left Blockberry Creative.
** Choi Yeyoung (K17) and Ryu Sion (K28) left Blockberry Creative & joined Sure Space.
* Some contestants debuted in new groups or debuted as soloists:
** Kim Suyeon (P10) debuted as a new member of Mystic Story's girl group, Billlie, under the stage name "Sheon". She debuted on November 27, 2021. She had her first release with the group on December 14 with their first digital single album The Collective Soul and Unconscious: Snowy Night.
** Su Ruiqi (P13) released her 8th digital single on December 14, 2021.
** Fu Yaning (P12) released her second digital single titled Starlight on December 27, 2021. She also starred in the iQiYi dramas My Heart and The Flowers Are Blooming.
** Ririka Kishida (P22), Hana Hayase (J18), Chang Ching (C23) and Lee Yunji (K26) debuted under FC Entertainment in a six-member group called ILY:1 on April 4, 2022. Lee Yunji and Chang Ching use the stage name "Ara" and "Rona" respectively while Ririka Kishida and Hana Hayase use their birth names.
** Shana Nonaka (P16) debuted in MLD Entertainment's new girl group, Lapillus, with the single "Hit Ya!" on June 20, 2022.
** Kim Hyerim (K15) debuted as a soloist on January 24, 2022.
** Yurina Kawaguchi (P14) debuted as a soloist on March 21, 2022, with her first single Look At Me.
** Kim Bora (P15) starred in the web-drama Jinx.
** Huh Jiwon (K16) starred in the web-drama Heart Way.
** Wen Zhe (P17) debuted as an actress.
** Yoon Jia (K11) debuted in Yes Im Entertainment group MiMiiRose on September 16, 2022.
** Miyu Ito (J19) debuted in 143 Entertainment's group LimeLight on February 14, 2023.
** Jeong Jiyoon (K12) joined Ichillin' and made her debut with the group on November 10, 2022.
** Ruan Ikema (P19) and Manami Nagai (P20) will debut in Kiss Entertainment's Japan-based girl group Kiss Girl's.
** Kotone Kamimoto (P24), Hsu Nientzu (C15), and Zhou Xinyu (P22) were revealed as TripleS' eleventh, thirteenth, and fifteenth member on January 2, March 20, and July 2, 2023, respectively.
** Momoko Okazaki (J21) joined Babymetal.
** Kim Doah (K10) debuted as a soloist on May 23, 2023, with the digital single "Dream Walking".
** An Jeongmin (K13) debuted as a soloist on June 24, 2023, with the digital single "Rainy Day", under the stage name JEOMi.
** You Dayeon (K19) debuted as a soloist on October 20, 2023, with the digital single "Down Down Down".
** Choi Yeyoung (K17) and Ryu Sion (K28) debuted in 5-member girl group Geenius, under Sure Space, on January 5, 2024.
** Guinn Myah (P11) debuted in TOP Media's new girl group Odd Youth on November 1, 2024.
** Risako Arai (J15) debuted in 5-member girl group UDTT, under SW Entertainment, with the pre-debut single "Retry" on December 11, 2024. The group will officially debut in early 2025.
** Nakamura Kyara (J33) debuted in Japan's based group BENNY, under TryCrew Entertainment, with the single "Woah", on February 21, 2025.
* Some contestants participated in other survival shows:
** Moana Yamauchi (J13) participated in the Japanese survival show iCON Z.
** Zhou Xinyu, Cui Wenmeixiu, Gu Yizhou, and Cai Bing participated in the Chinese survival show, "Great Dance Crew".
** Lee Sunwoo (K24) participated in Channel A's "Youth Star".
** You Dayeon (K19) participated in Show Me the Money 11, but was eliminated in the first round.
** Sakurai Miu (J11), Fujimoto Ayaka (J17), and Kanno Miyu (J31) participated in Produce 101 Japan The Girls. Miu placed 4th in the finale and will debut as a member of ME:I.
** Lee Sunwoo (K24) and Choi Hyerin (K27) participated in Universe Ticket
** Kim Bora and Huh Jiwon participated in Queendom Puzzle
** Ikema Ruan (J05), Aratake Rinka (J23), and Kamikura Rei (J27) participated in Produce Camp Asia: Thailand. Ruan placed 2nd in the finale and will debut as a member of Gen1es
** Hayashi Fuko (J20) participated in Mnet's I-Land 2: N/a in 2024.