# Japan at the 2018 Summer Youth Olympics

Japan participated at the 2018 Summer Youth Olympics in Buenos Aires, Argentina from 6 October to 18 October 2018. Japan competes in 23 events and brought home 39 medals. It was the rehearsal of the hosting Summer Olympics as Tokyo was the host of the 2020 games which was held from 23 July to 8 August 2021.

## Medalists

| Medal | Name | Sport | Event | Date |
| Gold | Yuka Ueno | Fencing | Girls' foil | 7 Oct |
| Gold | Ramu Kawai | Dancesport | B-Girls' | 8 Oct |
| Gold | Keita Dohi | Sport climbing | Boys' combined | 10 Oct |
| Gold | Yu Hanaguruma | Swimming | Boys' 200 m breaststroke | 10 Oct |
| Gold | Takeru Kitazono | Gymnastics | Boys' individual all-around | 11 Oct |
| Gold | Wataru Sasaki | Wrestling | Boys' Greco-Roman 51 kg | 12 Oct |
| Gold | Shiori Asaba | Swimming | Girls' 200 m breaststroke | 12 Oct |
| Gold | Takeru Kitazono | Gymnastics | Boys' floor | 13 Oct |
| Gold | Nonoka Ozaki | Wrestling | Girls' freestyle 57 kg | 13 Oct |
| Gold | Yuki Naito Naoki Tajima | Tennis | Mixed doubles | 14 Oct |
| Gold | Takeru Kitazono | Gymnastics | Boys' rings | 14 Oct |
| Gold | Takeru Kitazono | Gymnastics | Boys' parallel bars | 15 Oct |
| Gold | Takeru Kitazono | Gymnastics | Boys' horizontal bar | 15 Oct |
| Gold | Haruto Deguchi | Athletics | Boys' 400 m hurdles | 16 Ovt |
| Gold | Kokoro Sakaji | Karate | Girls' 59 kg | 17 Oct |
| Silver | Shuta Tanaka | Sport climbing | Boys' combined | 10 Oct |
| Silver | Miu Hirano | Table tennis | Girls' singles | 10 Oct |
| Silver | Tomokazu Harimoto | Table tennis | Boys' singles | 10 Oct |
| Silver | Keisuke Yoshida | Swimming | Boys' 800 m freestyle | 11 Oct |
| Silver | Mayuka Yamamoto | Swimming | Girls' 50 m freestyle | 12 Oct |
| Silver | Yuki Naito Naho Sato | Tennis | Girls' doubles | 13 Oct |
| Silver | Miu Hirano Tomokazu Harimoto | Table tennis | Mixed team | 15 Oct |
| Silver | Kazuki Furusawa | Athletics | Boys' pole vault | 16 Oct |
| Silver | Masaki Yamaoka | Karate | Boys' 61 kg | 17 Oct |
| Silver | Rinka Tahata | Karate | Girls' 53 kg | 17 Oct |
| Silver | Mai Miyamoto Sara Oino Yuria Sutoh Rinka Yokoyama Ichika Arai Aki Ikeuchi Miu Maeda Mitsuki Kobayashi Rikako Yamakawa Mirano Abe | Futsal | Girls' tournament | 17 Oct |
| Silver | Sakura Sawashima | Karate | Girls' 59 kg | 18 Oct |
| Bronze | Keisuke Yoshida | Swimming | Boys' 400 m freestyle | 7 Oct |
| Bronze | Shigeyuki Nakarai | Dancesport | B-Boys' | 8 Oct |
| Bronze | Taku Taniguchi | Swimming | Boys' 100 m breaststroke | 8 Oct |
| Bronze | Kanami Tanno Yuma Oshimo | Cycling | Mixed BMX freestyle park | 11 Oct |
| Bronze | Miku Kojima Mayuka Yamamoto Nagisa Ikemoto Shiori Asaba | Swimming | Girls' 4 × 100 m medley relay | 11 Oct |
| Bronze | Kodai Naraoka | Badminton | Boys' singles | 12 Oct |
| Bronze | Shu Yamada | Wrestling | Boys' Greco-Roman 71 kg | 12 Oct |
| Bronze | Miku Kojima Taku TaniguchI Shinnosuke Ishikawa Nagisa Ikemoto | Swimming | Mixed 4 × 100 m medley relay | 12 Oct |
| Bronze | Yuka Kagami | Wrestling | Girls' freestyle 73 kg | 13 Oct |
| Bronze | Koki Wada | Athletics | Boys' long jump | 15 Oct |
| Bronze | Seiryo Ikeda | Athletics | Boys' 100 m | 15 Oct |
| Bronze | Ryo EtoJoh OhbaRyosuke KanKaito NakanishiKentaro FujiiJunya MatsumotoKippei IshidaHaruhiko UemuraTaisei KonishiTaira MainKanji FutamuraHibiki Yamada | Rugby sevens | Boys' tournament | 15 Oct |
Medals by sport :
| Sport | | | | Total |
| Gymnastics | 5 | 0 | 0 | 5 |
| Swimming | 2 | 2 | 4 | 8 |
| Wrestling | 2 | 0 | 2 | 4 |
| Karate | 1 | 3 | 0 | 4 |
| Athletics | 1 | 1 | 2 | 4 |
| Sport climbing | 1 | 1 | 0 | 2 |
| Tennis | 1 | 1 | 0 | 2 |
| Dancesport | 1 | 0 | 1 | 2 |
| Fencing | 1 | 0 | 0 | 1 |
| Table tennis | 0 | 3 | 0 | 3 |
| Futsal | 0 | 1 | 0 | 1 |
| Badminton | 0 | 0 | 1 | 1 |
| Cycling | 0 | 0 | 1 | 1 |
| Rugby sevens | 0 | 0 | 1 | 1 |
| Total | 15 | 12 | 12 | 39 |

## Competitors

| Sport | Boy | Girl | Total |
| Archery | 1 | 1 | 2 |
| Athletics | 8 | 6 | 14 |
| Badminton | 1 | 1 | 2 |
| Cycling | 2 | 2 | 4 |
| Dancesport | 1 | 1 | 2 |
| Fencing | 2 | 1 | 3 |
| Futsal | – | 10 | 10 |
| Golf | 1 | 1 | 2 |
| Gymnastics | 2 | 3 | 5 |
| Karate | 3 | 3 | 6 |
| Modern pentathlon | 0 | 1 | 1 |
| Rowing | 1 | 0 | 1 |
| Rugby sevens | 12 | – | 12 |
| Sailing | 1 | 0 | 1 |
| Shooting | 0 | 1 | 1 |
| Sport climbing | 2 | 1 | 3 |
| Swimming | 4 | 4 | 8 |
| Table tennis | 1 | 1 | 2 |
| Taekwondo | 1 | 0 | 1 |
| Tennis | 1 | 2 | 3 |
| Triathlon | 1 | 1 | 2 |
| Weightlifting | 0 | 1 | 1 |
| Wrestling | 3 | 2 | 5 |
| Total | 48 | 43 | 91 |

## Archery

Japan qualified two archers based on its performance at the 2017 World Archery Youth Championships.

### Individual

| Athlete | Event | Ranking round | Ranking round | Round of 32 | Round of 16 | Quarterfinals | Semifinals | Final / BM | Rank |
| Athlete | Event | Score | Seed | Opposition Score | Opposition Score | Opposition Score | Opposition Score | Opposition Score | Rank |
| Tetsuya Aoshima | Boys' Individual | 654 | 22 | Tolba (EGY) L 5–6 | did not advance | did not advance | did not advance | did not advance | 17 |
| Ruka Uehara | Girls' Individual | 667 | 2 | Jones (NZL) L 5–6 | did not advance | did not advance | did not advance | did not advance | 17 |

### Team

| Athletes | Event | Ranking round | Ranking round | Round of 32 | Round of 16 | Quarterfinals | Semifinals | Final / BM | Rank |
| Athletes | Event | Score | Seed | Opposition Score | Opposition Score | Opposition Score | Opposition Score | Opposition Score | Rank |
| Tetsuya Aoshima (JPN) Èlia Canales (ESP) | Mixed team | 1299 | 19 | Naumova (UKR) Eyeni (CIV) L 4–5 | did not advance | did not advance | did not advance | did not advance | 17 |
| Ruka Uehara (JPN) Louis Gino Aurelien Juhel (MRI) | Mixed team | 1273 | 30 | Kharitonova (RUS) Rezowan (BAN) L 4–5 | did not advance | did not advance | did not advance | did not advance | 17 |

## Athletics
### Track & road events

| Athlete | Event | Stage 1 | Stage 1 | Stage 2 | Stage 2 | Total | Total |
| Athlete | Event | Time | Rank | Time | Rank | Time | Rank |
| Seiryo Ikeda | 100 m | 10.82 | 3 | 10.30 | 3 | 21.12 | |
| Kosuke Ishida | 1500 m | 3:57.25 | 11 | 11:52 | 5 | 16 | 7 |
| Rintaro Kajiyama | 3000 m | 8:22.15 | 5 | 12:10 | 8 | 13 | 6 |
| Haruto Deguchi | 400 m hurdles | 51.40 | 1 | 51.28 | 1 | 1:42.68 | |
| Yusuke Iwakawa | 5000 m walk | 21:49.40 | 10 | 23:20.84 | 12 | 45:10.24 | 12 |

### Field Events

| Athlete | Event | Stage 1 | Stage 1 | Stage 2 | Stage 2 | Total | Total |
| Athlete | Event | Time | Rank | Time | Rank | Time | Rank |
| Kazuki Furusawa | Pole vault | 5.10 | 3 | 5.22 | 2 | 10.32 | |
| Koki Wada | Long jump | 7.46 | 4 | 7.66 | 3 | 15.12 | |
| Kentaro Nakamura | Javelin throw | 66.31 | 13 | 64.55 | 12 | 130.86 | 12 |

### Track & road events

| Athlete | Event | Stage 1 | Stage 1 | Stage 2 | Stage 2 | Total | Total |
| Athlete | Event | Time | Rank | Time | Rank | Time | Rank |
| Takako Niisaka | 100 m | 12.22 | 7 | 11.65 | 8 | 23.87 | 8 |
| Maki Ueda | 800 m | 2:09.91 | 8 | 2:10.06 | 5 | 4:19.97 | 7 |
| Yuki Kanemitsu | 1500 m | 4:24.41 | 4 | 13:13 | 3 | 7 | 4 |
| Miyaka Sugata | 3000 m | 9:21.16 | 5 | 13:59 | 11 | 16 | 9 |

### Field Events

| Athlete | Event | Stage 1 | Stage 1 | Stage 2 | Stage 2 | Total | Total |
| Athlete | Event | Time | Rank | Time | Rank | Time | Rank |
| Azuki Nakatsugawa | Long jump | 5.86 | 6 | 6.14 | 5 | 12.00 | 5 |
| Yuika Nakamura | Javelin throw | 43.62 | 14 | DNS | - | - | - |
$^a$ Cross Country

## Badminton

Japan qualified two players based on the Badminton Junior World Rankings.

### Singles

| Athlete | Event | Group Stage | Group Stage | Group Stage | Group Stage | Quarterfinal | Semifinal | Final / BM | Final / BM |
| Athlete | Event | Opposition Score | Opposition Score | Opposition Score | Rank | Opposition Score | Opposition Score | Opposition Score | Rank |
| Kodai Naraoka | Boys' singles | Chang Ho Kim (FIJ) W (21–7, 21–5) | Cristian Savin (MDA) W (21–8, 21–13) | Dmitriy Panarin (KAZ) W (21–9, 21–12) | 1 Q | Chen Shiau-cheng (TPE) W (21–11, 21–11) | Lakshya Sen (IND) L (21–14, 15–21, 22–24) | Arnaud Merklé (FRA) W (21–17, 24–26, 22–20) | |
| Hirari Mizui | Girls' singles | Léonice Huet (FRA) W (21–14, 21–16) | Halla Bouksani (ALG) W (21–1, 21–9) | Wang Zhiyi (CHN) L (10–21, 21–17, 16–21) | 2 | did not advance | did not advance | did not advance | 9 |

### Team

| Athlete | Event | Group stage | Group stage | Group stage | Group stage | Quarterfinal | Semifinal | Final / BM | Rank |
| Athlete | Event | Opposition Score | Opposition Score | Opposition Score | Rank | Opposition Score | Opposition Score | Opposition Score | Rank |
| Team Theta Kodai Naraoka (JPN) Hirari Mizui (JPN) Julien Carraggi (BEL) Mohamed Mostafa Kamel (EGY) Lukas Resch (GER) Zecily Fung (AUS) Jaqueline Lima (BRA) Tereza Švábíková (CZE) | Mixed Teams | Sigma (MIX) L (100–110) | Omega (MIX) L (100–110) | Gamma (MIX) L (107–110) | 4Q | Delta (MIX) W (110–93) | Alpha (MIX) L (90–110) | Zeta (MIX) W (110–107) | |

## Cycling

Japan qualified a boys' and girls' combined team based on its ranking in the Youth Olympic Games Junior Nation Rankings. They also qualified a mixed BMX racing team based on its ranking in the Youth Olympic Games BMX Junior Nation Rankings and two athletes in BMX freestyle based on its performance at the 2018 Urban Cycling World Championship.
* Boys' combined team – 1 team of 2 athletes
* Girls' combined team – 1 team of 2 athletes
* Mixed BMX racing team – 1 team of 2 athletes
* Mixed BMX freestyle – 1 boy and 1 girl

## Dancesport

Japan qualified two dancers based on its performance at the 2018 World Youth Breaking Championship.
* B-Boys – Shigekix
* B-Girls – Ram

## Fencing

Japan qualified three athletes based on its performance at the 2018 Cadet World Championship.
| Athlete | Event | Group Stage | Group Stage | Group Stage | Group Stage | Group Stage | Group Stage | Group Stage | Round of 16 | Quarterfinals | Semifinals | Final / BM / FM | Final / BM / FM |
| Athlete | Event | Opposition Score | Opposition Score | Opposition Score | Opposition Score | Opposition Score | Opposition Score | Rank | Opposition Score | Opposition Score | Opposition Score | Opposition Score | Rank |
| Seiya Asami | Boys' épée | Ignacio Pérez Contreras (ARG) W (5–1) | Khasan Baudunov (KGZ) L (3–4) | Paul Veltrup (GER) L (2–5) | Seraphim Hsieh Jarov (CAN) W (5–3) | Artur Tolasov (RUS) W (5–1) | — | 2 | — | Khasan Baudunov (KGZ) L (1–5) | Did not advance | Did not advance | 6 |
| Hibiki Kato | Boys' sabre | Samuel Jarry (FRA) L (1–5) | Andrei Păștin (ROU) W (5–1) | Matias Ríos (ARG) W (5–1) | Hudson Santana (PUR) L (4–5) | Alonso Santamaría (ESP) L (3–5) | — | 4 | Amirhossein Shaker (IRI) W (15–9) | Hyun Jun (KOR) L (12–15) | Did not advance | Did not advance | 8 |
| Yuka Ueno | Girls' foil | Giorgia Salmas (AUS) W (5–0) | Venissia Thépaut (FRA) W (5–3) | Rebeca Cândescu (ROU) W (5–1) | Christelle Joy Ko (HKG) W (5–1) | Anabella Acurero (VEN) W (5–0) | Noha Hany (EGY) W (5–1) | 1 | — | Christelle Joy Ko (HKG) W (13–3) | Anabella Acurero (VEN) W (8–4) | Martina Favaretto (ITA) W (15–12) | |

## Futsal
### Summary

| Team | Event | Group Stage | Group Stage | Group Stage | Group Stage | Group Stage | Semifinal | Final / BM | Final / BM |
| Team | Event | Opposition score | Opposition score | Opposition score | Opposition score | Rank | Opposition score | Opposition score | Rank |
| Japan | Girls' tournament | Cameroon W 6–2 | Chile W 4–1 | Dominican Republic W 6–2 | Portugal L 0–2 | 2 | Spain W 3–2 | Portugal L 1–4 | |

### Group D

| Pos | Teamvte | Pld | W | D | L | GF | GA | GD | Pts | Qualification |
| 1 | Portugal | 4 | 4 | 0 | 0 | 37 | 2 | +35 | 12 | Semi-finals |
| 2 | Japan | 4 | 3 | 0 | 1 | 16 | 7 | +9 | 9 | Semi-finals |
| 3 | Cameroon | 4 | 2 | 0 | 2 | 16 | 13 | +3 | 6 | |
| 4 | Chile | 4 | 0 | 1 | 3 | 6 | 27 | −21 | 1 | |
| 5 | Dominican Republic | 4 | 0 | 1 | 3 | 6 | 32 | −26 | 1 | |

### Finals
## Golf
### Individual

| Athlete | Event | Round 1 | Round 1 | Round 2 | Round 2 | Round 2 | Round 3 | Round 3 | Round 3 | Total | Total | Total |
| Athlete | Event | Score | Rank | Score | Total | Rank | Score | Total | Rank | Score | Par | Rank |
| Kagetsu Tsuruse | Girls' Individual | 79 (+9) | 22 | 77 (+7) | 156 | 19 | 79 (+9) | 235 | 28 | 235 | +25 | 27 |
| Ryou Hitsatsune | Boys' Individual | 75 (+5) | 20 | 68 (-2) | 143 | 1 | 70 (0) | 213 | 4 | 213 | +3 | 5 |

### Team

| Athletes | Event | Round 1 (Fourball) | Round 1 (Fourball) | Round 2 (Foursome) | Round 2 (Foursome) | Round 3 (Individual Stroke) | Round 3 (Individual Stroke) | Round 3 (Individual Stroke) | Round 3 (Individual Stroke) | Total | Total | Total |
| Athletes | Event | Score | Rank | Score | Rank | Girl | Boy | Total | Rank | Score | Par | Rank |
| Kagetsu Tsuruse Ryou Hitsatsune | Mixed team | 64 (-6) | 6 | 74 (+4) | 15 | 76 | 70 | 146 (+6) | 11 | 284 | +4 | 9 |

## Gymnastics
### Artistic

Japan qualified two gymnasts based on its performance at the 2018 Asian Junior Championship.
| Athlete | Event | Apparatus | Apparatus | Apparatus | Apparatus | Apparatus | Apparatus | Total | Rank |
| Athlete | Event | F | PH | R | V | PB | HB | Total | Rank |
| Takeru Kitazono | Qualification | 13.500 | 14.133 | 13.700 | 14.100 | 14.266 | 13.600 | 83.299 | 1 Q |
| Takeru Kitazono | All-around | 13.833 | 13.966 | 13.466 | 14.233 | 13.000 | 13.800 | 83.299 | |
| Takeru Kitazono | Floor | | | | | | | 13.633 | |
| Takeru Kitazono | Parallel bars | | | | | | | 12.666 | 6 |
| Takeru Kitazono | Rings | | | | | | | 13.533 | |
| Takeru Kitazono | Parallel bars | | | | | | | 14.166 | |
| Takeru Kitazono | Horizontal bar | | | | | | | 13.566 | |
| Athlete | Event | Apparatus | Apparatus | Apparatus | Apparatus | Total | Rank |
| Athlete | Event | V | UB | BB | F | Total | Rank |
| Chiharu Yamada | Qualification | 13.100 | 9.733 | 11.166 | 12.566 | 46.565 | 21 |
| Chiharu Yamada | Floor | | | | | 12.000 | 6 |

### Rhythmic

Japan qualified one gymnast based on its performance at the 2018 Asian Junior Championship.

#### Individual

| Athlete | Event | Qualification | Qualification | Qualification | Qualification | Qualification | Qualification | Final | Final | Final | Final | Final | Final |
| Athlete | Event | Hoop | Ball | Clubs | Ribbon | Total | Rank | Hoop | Ball | Clubs | Ribbon | Total | Rank |
| Aino Yamada | Individual | 14.900 | 14.850 | 15.450 | 14.250 | 59.450 | 6 Q | 15.500 | 15.300 | 15.000 | 12.400 | 58.200 | 8 |

### Trampoline

Japan qualified two gymnasts based on its performance at the 2018 Asian Junior Championship.
* Boys' trampoline – 1 quota
* Girls' trampoline – 1 quota
| Athlete | Event | Qualification | Qualification | Qualification | Qualification | Final | Final |
| Athlete | Event | Routine 1 | Routine 2 | Total | Rank | Score | Rank |
| Takumi Fujimoto | Boys | | | 50.975 | 12 | Did not advance | Did not advance |
| Yuki Okuno | Girls | 42.440 | 50.395 | 92.835 | 6 Q | 50.760 | 5 |

## Karate

Japan qualified three athlete based on the rankings in the Buenos Aires 2018 Olympic Standings. Later, they qualified three more athletes based on its performance at one of the Karate Qualification Tournaments.
| Athlete | Event | Group Stage | Group Stage | Group Stage | Group Stage | Semifinal | Final / BM | Final / BM |
| Athlete | Event | Opposition Score | Opposition Score | Opposition Score | Rank | Opposition Score | Opposition Score | Rank |
| Masaki Yamaoka | Boys' 61 kg | Pedropablo de la Roca (GUA) W (4–0) | Alireza Farajikouhikheili (IRI) W (5–0) | Oussama Edari (MAR) D (0–0) | 1 | Fahik Veseli (MKD) W (8–0) | Mohammed Al-Assiri (KSA) L (0–8) | |
| Kotaro Nakamura | Boys' 68 kg | Yassine Sekouri (MAR) L (2–8) | Abilmansur Batyrgali (KAZ) L (0–3) | Juan Salsench (ARG) D (0–0) | 3 | Did not advance | Did not advance | Did not advance |
| Keisei Sakiyama | Boys' +68 kg | Tomáš Kósa (SVK) W (1–0) | Navid Mohammadi (IRI) W (2–0) | Sean McCarthy Crean (IRL) L (1–2) | 3 | Did not advance | Did not advance | Did not advance |
| Rinka Tahata | Girls' 53 kg | Aika Okazaki (THA) D (3–3) | Tânia de Barros (POR) W (2–0) | Fatemeh Khonakdartarsi (IRI) W (1–0) | 1 | Dildora Alikulova (UZB) W (2–0) | Yasmin Nasr Elgewily (EGY) L (1–2) | |
| Kokoro Sakaji | Girls' 59 kg | Marta Ossipova (EST) W (4–0) | Zsófia Baranyi (HUN) W (1–0) | Ivana Perović (SRB) W (1–0) | 1 | Mobina Heydariozomcheloei (IRI) D (0–0) | Anna Chernysheva (RSA) W (3–0) | |
| Sakura Sawashima | Girls' +59 kg | Laura Lyck (DEN) W (2–0) | Negin Altooni (IRI) L (1–5) | Janessa Fonseca (PUR) W (3–0) | 1 | Lauren Salisbury (GBR) W (9–1) | Annika Sælid (NOR) L (0–3) | |

## Rowing

Japan qualified one boat based on its performance at the 2018 Asian Youth Olympic Games Qualification Regatta.
* Boys' single sculls – 1 athlete

## Rugby sevens
### Boys' tournament
#### Summary

| Team | Event | Group Stage | Group Stage | Group Stage | Group Stage | Group Stage | Group Stage | Bronze medal game | Bronze medal game |
| Team | Event | Opposition score | Opposition score | Opposition score | Opposition score | Opposition score | Rank | Opposition score | Rank |
| Japan | Boys' tournament | South Africa W 14–12 | Argentina L 0–45 | Samoa W 29–0 | United States D 17–17 | France L 14–29 | 3 | South Africa W 28–5 | |

#### Group Stage

| Pos | Team | Pld | W | D | L | PF | PA | PD | Pts |
| 1 | Argentina | 5 | 5 | 0 | 0 | 180 | 38 | +142 | 15 |
| 2 | France | 5 | 4 | 0 | 1 | 111 | 65 | +46 | 13 |
| 3 | Japan | 5 | 2 | 1 | 2 | 74 | 103 | −29 | 10 |
| 4 | South Africa | 5 | 2 | 0 | 3 | 79 | 84 | −5 | 9 |
| 5 | United States | 5 | 0 | 2 | 3 | 67 | 120 | −53 | 7 |
| 6 | Samoa | 5 | 0 | 1 | 4 | 48 | 149 | −101 | 6 |
* 13 October 2018 13:15
| South Africa | 12–14 | Japan |
| Try: Maubane 3'c Kellerman 7'm Con: Hattingh (1/2) 3' | Report | Try: Nakanishi 6'c Konishi 11'c Con: Yamada (2/2) 7', 12' |
* Club Atlético San Isidro, Buenos Aires Referee: Nehuen Jauri Rivero (Argentina)
* 13 October 2018 17:10
| Argentina | 45–0 | Japan |
| Try: Cinti Luna (2) 2'c, 9'c Vanni 4'm González 6'c Mendy 8'c Graziano 11'm Moneta 13'c Con: Roger (2/3) 3', 6' Elicagaray (3/4) 8', 9', 13' | Report | |
* Club Atlético San Isidro, Buenos Aires Referee: Francisco González (Uruguay)
* 14 October 2018 10:05
| Japan | 29–0 | Samoa |
| Try: Fujii (3) 0'm, 1'm, 4'c Konishi 10'c Nakanishi 13'm Con: Yamada (2/5) 5', 10' | Report | |
* Club Atlético San Isidro, Buenos Aires Referee: Damián Schneider (Argentina)
* 14 October 2018 12:45
| United States | 17–17 | Japan |
| Try: Sione 3'c Kruse 10'm Green 13'm Con: Sione (1/3) 3' | Report | Try: Konishi 4'c Nakanashi 6'm Yamada 8'm Con: Konishi (1/1) 5' Ishida (0/1) Uemura (0/1) |
* Club Atlético San Isidro, Buenos Aires Referee: Nehuen Jauri Rivero (Argentina)
* 15 October 2018 11:55
| France | 29–14 | Japan |
| Try: Dridi 1'c Dulon 4'm Randle 6'c Trouabal 11'm Tani 13'm Con: Bellot (1/2) 2' Tiberghien (1/2) 7' Germain (0/1) | Report | Try: Konishi 3'c Fujii 9'c Con: Konishi (1/1) 4' Yamada (1/1) 9' |
* Club Atlético San Isidro, Buenos Aires Referee: Paulo Duarte (Portugal)

#### Bronze medal match

* 15 October 2018 15:10
| Japan | 28–5 | South Africa |
| Try: Fujii 2'c Nakanishi 3'c Konishi (2) 8'c, 12'c Con: Konishi (4/4) 2', 3', 9', 12' | Report | Try: Maubane 13'm Con: Braude (0/1) |
* Club Atlético San Isidro, Buenos Aires Referee: Damián Schneider (Argentina)

## Sailing

Japan qualified one boat based on its performance at the 2018 Singapore Open (Asian Techno 293+ Qualifiers).
* Boys' Techno 293+ – 1 boat

## Shooting

* Girls Rifle – Aoi Takagi

### Individual

| Athlete | Event | Qualification | Qualification | Final | Final |
| Athlete | Event | Points | Rank | Points | Rank |
| Aoi Takagi | Girls' 10m air rifle | 615.1 | 15 | did not advance | did not advance |

### Team

| Athletes | Event | Qualification | Qualification | Round of 16 | Quarterfinals | Semifinals | Final / BM | Final / BM |
| Athletes | Event | Points | Rank | Opposition Result | Opposition Result | Opposition Result | Opposition Result | Rank |
| Aoi Takagi (JPN) Maximilian Ulbrich (GER) | Mixed 10 metre air rifle | 825.1 | 7 Q | Martínez López (MEX) Wadlegger (AUT) L 7–10 | did not advance | did not advance | did not advance | did not advance |

## Sport climbing

Japan qualified two sport climbers based on its performance at the 2017 World Youth Sport Climbing Championships. They also qualified a female climber based on its performance at the 2017 Asian Youth Sport Climbing Championships.
* Boys' combined – 2 quotas (Keita Dohi, Shuta Tanaka)
* Girls' combined – 1 quota (Mao Nakamura)

## Swimming
### Boys

| Athlete | Event | Heat | Heat | Semifinal | Semifinal | Final | Final |
| Athlete | Event | Time | Rank | Time | Rank | Time | Rank |
| Keisuke Yoshida | 200 m freestyle | 1:48.97 | 1 Q | — | — | 1:48.75 | 5 |
| Keisuke Yoshida | 400 m freestyle | 3:51.68 | 1 Q | — | — | 3:48.68 | |
| Keisuke Yoshida | 800 m freestyle | — | — | — | — | 7:53.85 | |
| Taku Taniguchi | 50 m breaststroke | 28.28 | 3 Q | 28.22 | 4 | 28.20 | 4 |
| Taku Taniguchi | 100 m breaststroke | 1:01.68 | 3 Q | 1:02.08 | 5 Q | 1:01.40 | |
| Taku Taniguchi | 200 m breaststroke | 2:16.67 | 8 Q | — | — | 2:15.21 | 5 |
| Yu Hanaguruma | 50 m breaststroke | 29.18 | 16 Q | 29.01 | 14 | Did not advance | Did not advance |
| Yu Hanaguruma | 100 m breaststroke | 1:02.22 | 4 Q | 1:01.99 | 4 Q | 1:01.62 | 4 |
| Yu Hanaguruma | 200 m breaststroke | 2:13.58 | 1 Q | — | — | 2:11.63 | |
| Shinnosuke Ishikawa | 50 m butterfly | 24.64 | 16 Q | 24.76 | 14 | Did not advance | Did not advance |
| Shinnosuke Ishikawa | 100 m butterfly | 53.57 | 7 Q | 52.67 | 4 Q | 52.52 | 4 |
| Shinnosuke Ishikawa | 200 m butterfly | 2:01.47 | 7 Q | — | — | 1:59.42 | 6 |
| Keisuke Yoshida Taku Taniguchi Shinnosuke Ishikawa Yu Hanaguruma | 4 × 100 m freestyle relay | — | — | — | — | 3:26.80 | 6 |
| Keisuke Yoshida Yu Hanaguruma Shinnosuke Ishikawa Taku Taniguchi | 4 × 100 m medley relay | 3:45.34 | 3 Q | — | — | DSQ | DSQ |

### Girls

| Athlete | Event | Heat | Heat | Semifinal | Semifinal | Final | Final |
| Athlete | Event | Time | Rank | Time | Rank | Time | Rank |
| Mayuka Yamamoto | 50 m freestyle | 25.80 | 6 Q | 25.62 | 7 Q | 25.39 | |
| Mayuka Yamamoto | 100 m freestyle | 55.95 | 4 Q | 56.37 | 9 | Did not advance | Did not advance |
| Mayuka Yamamoto | 50 m butterfly | 26.84 | 3 Q | 27.12 | 8 Q | 27.17 | 7 |
| Nagisa Ikemoto | 50 m freestyle | 26.52 | 18 | Did not advance | Did not advance | Did not advance | Did not advance |
| Nagisa Ikemoto | 100 m freestyle | 55.51 | 2 Q | 55.25 | 4 Q | 55.37 | 4 |
| Nagisa Ikemoto | 200 m freestyle | 2:01.18 | 6 Q | — | — | 1:59.89 | 5 |
| Shiori Asaba | 50 m breaststroke | 33.46 | 25 | Did not advance | Did not advance | Did not advance | Did not advance |
| Shiori Asaba | 100 m breaststroke | 1:09.27 | 3 Q | 1:09.50 | 6 Q | 1:09.57 | 8 |
| Shiori Asaba | 200 m breaststroke | 2:29.12 | 1 Q | — | — | 2:26.80 | |
| Miku Kojima | 200 m individual medley | 2:15.37 | 3 Q | — | — | 2:15.09 | 4 |
| Miku Kojima Mayuka Yamamoto Nagisa Ikemoto Shiori Asaba | 4 × 100 m freestyle relay | — | — | — | — | 3:49.27 | |

### Mixed

| Athlete | Event | Heat | Heat | Final | Final |
| Athlete | Event | Time | Rank | Time | Rank |
| Keisuke Yoshida Taku Taniguchi Mayuka Yamamoto Nagisa Ikemoto Shinnosuke Ishikawa | 4 × 100 m freestyle relay | 3:35.95 | 6 Q | 3:34.18 | 7 |
| Miku Kojima Taku TaniguchI Shinnosuke Ishikawa Nagisa Ikemoto Yu Hanaguruma | 4 × 100 m medley relay | 3:54.14 | 2 Q | 3:51.74 | |
* $^a$ Swimmers who participated in the heats only.
* $^b$ Swimmers who participated in the heats only and received medals.

## Table tennis

Japan qualified two table tennis players based on its performance at the Asian Continental Qualifier.
* Boys' singles – Tomokazu Harimoto
* Girls' singles – Miu Hirano

## Taekwondo

| Athlete | Event | Round of 16 | Quarterfinals | Semifinals | Final | Final |
| Athlete | Event | Opposition Score | Opposition Score | Opposition Score | Opposition Score | Rank |
| Hidetaka Maeda | Boys' 55 kg | Mason Yarrow (GBR) W (29–6) | Georgii Popov (RUS) L (13–34) | did not advance | did not advance | did not advance |

## Tennis

| Athlete | Event | First round | Second round | Quarterfinals | Semifinals | Final / BM | Final / BM |
| Athlete | Event | Opposition Score | Opposition Score | Opposition Score | Opposition Score | Opposition Score | Rank |
| Naoki Tajima | Boys' singles | Arnaud Bovy (BEL) W (6–4, 6-2) | Hugo Gaston (FRA) L (3–6, 2-6) | did not advance | did not advance | did not advance | did not advance |
| Naoki Tajima Mu Tao (CHN) | Boys' doubles | Filip Cristian Jianu Daniel Michalski (MIX) W (6–7, 6-3) | — | Sebastián Báez Facundo Díaz Acosta (ARG) L (0–6, 1-6) | did not advance | did not advance | did not advance |
| Yuki Naito | Girls' singles | Wang Xiyu (CHN) W (7–6, 7-5) | Kamilla Rakhimova (RUS) W (7–6, 3-6, 6-4) | Camila Osorio (COL) L (7–6, 3-6, 1-6) | did not advance | did not advance | did not advance |
| Naho Sato | Girls' singles | Viktoriia Dema (UKR) L (1–6, 4-6) | did not advance | did not advance | did not advance | did not advance | did not advance |
| Yuki Naito Naho Sato | Girls' doubles | Georgia Drummy Ana Makatsaria (MIX) W (6–1, 7-5) | — | Margaryta Bilokin Viktoriia Dema (UKR) W (7–5, 5-7) | Wang Xinyu Wang Xiyu (CHN) W (6–4, 4-6) | Kaja Juvan Iga Świątek (MIX) L (7–6, 5-7) | |
| Yuki Naito Naoki Tajima | Mixed doubles | Ana Makatsaria Patrick Sydow (MIX) W (6–0, 6-1) | Iga Świątek Daniel Michalski (POL) W w/o | Joanna Garland Tseng Chun-hsin (TPE) W (6–1, 6-0) | Clara Burel Hugo Gaston (FRA) W (6–1, 7-5) | Camila Osorio Nicolás Mejía (COL) L (6–2, 6-3) | |
| Naho Sato Gilbert Soares Klier Júnior (BRA) | Mixed doubles | Georgia Drummy Delmas N'tcha (MIX) W (6–1, 6-1) | Oksana Selekhmeteva Carlos López Montagud (MIX) L (4-6, 7-6$^8$, [6]-[10]) | did not advance | did not advance | did not advance | did not advance |

## Triathlon

Japan qualified two athletes based on its performance at the 2018 Asian Youth Olympic Games Qualifier.

### Individual

| Athlete | Event | Swim (750m) | Trans 1 | Bike (20 km) | Trans 2 | Run (5 km) | Total Time | Rank |
| Teppei Tokuyama | Boys | 9:59 | 0:29 | 29:10 | 0:34 | 17:38 | 57:50 | 23 |
| Maki Uchida | Girls | 9:32 | 0:55 | 32:16 | 0:32 | 22:05 | 1:05:20 | 25 |

### Relay

| Athlete | Event | Total Times per Athlete (Swim 250m, Bike 6.6 km, Run 1.8 km) | Total Group Time | Rank |
| Asia 1 Lee Jung-won (KOR) Teppei Tokuyama (JPN) Emma Ada Middleditch (SGP) Daniil Zubtsov (KAZ) | Mixed Relay | 22:57 (8) 21:44 (9) 24:01 (7) 23:15 (10) | 1:31:57 | 10 |
| Asia 2 Maki Uchida (JPN) Hung Tik Long (HKG) Yu Xinying (CHN) Chong Xian Hao (MAS) | Mixed Relay | 23:40 (13) 24:22 (14) 25:21 (11) 23:26 (11) | 1:36:49 1P | 13 |

## Weightlifting

Japan qualified one athlete based on its performance at the 2018 Asian Youth Championships.
| Athlete | Event | Snatch | Snatch | Clean & jerk | Clean & jerk | Total | Rank |
| Athlete | Event | Result | Rank | Result | Rank | Total | Rank |
| Sumire Hashimoto | Girls' -63 kg | 75 | 7 | 95 | 8 | 170 | 8 |

## Wrestling
### Boys

| Athlete | Event | Group Stage | Group Stage | Group Stage | Final / BM / FM | Final / BM / FM |
| Athlete | Event | Opposition Score | Opposition Score | Rank | Opposition Score | Rank |
| Hayato Fujita | freestyle 55 kg | Vladyslav Ostapenko (UKR) L (4–10) | Robert Howard (USA) L (2–13) | 3 | Gavin Whitt (GUM) W (10–0) | 5 |
| Wataru Sasaki | Greco-Roman 51 kg | Mehdi Jouini (TUN) W (9–0) | Axel Salas (MEX) W (10–1) | 1 | Giorgi Tokhadze (GEO) W (11–7) | |
| Shu Yamada | Greco-Roman 71 kg | Lynch Santos (GUM) W (8–0) | Stepan Starodubtsev (RUS) L (2–4) | 2 | Lamjed Maafi (TUN) W (4–0) | |

### Girls

| Athlete | Event | Group Stage | Group Stage | Group Stage | Group Stage | Group Stage | Final / BM | Final / BM |
| Athlete | Event | Opposition Score | Opposition Score | Opposition Score | Opposition Score | Rank | Opposition Score | Rank |
| Nonoka Ozaki | freestyle 57 kg | Andrea López (MEX) W (8–2) | Kaetlyn-Rae Quintanilla (GUM) W (10–0) | Anastasia Blayvas (GER) W (10–0) | Hala Ahmed (EGY) W (10–0) | 1 | Anna Szél (HUN) W (10–0) | |
| Yuka Kagami | freestyle 73 kg | Milaimys Marín (CUB) L (1–4) | Ioana Ludgate (ASA) W (10–0) | Julia Fridlund (SWE) W (12–2) | Anika White (CAN) W (10–0) | 2 | Kseniya Dzibuk (BLR) W (8–0) | |