Seishun Jidai 1.2.3! / Bicycle Daiseikou!

Seishun Jidai 1. 2. 3! / Bicycle Daiseikou! (青春時代1. 2. 3!／バイセコー大成功!, Age of Youth 1. 2. 3! / Bicycle Big Success!) is the second single of the subgroup Petitmoni. It was released on July 26, 2000 and sold 484,160 copies. It went to number one on the Oricon Charts in Japan.
==Tracklist==
#Seishun Jidai 1.2.3!
#Bicycle Daiseikou!
#Seishun Jidai 1.2.3! (Instrumental)
#Bicycle Daiseikou! (Instrumental)
==Featured Members==
*Yasuda Kei
*Goto Maki
*Yoshizawa Hitomi (debut)
==Single Information==
;Seishun Jidai 1.2.3!
*Lyrics, Composition, Chorus: Tsunku
*Arrangement, Acoustic Piano, Programming: Maejima Yasuaki
*Wood Bass: Mizutani Hiroaki
*Guitar: Suzuki Shunsuke
*Drums: Sano Yasuo
*Percussion: Ohgmi Gen
*Trumpet: Sasaki Shiro (Bacchus), Suzuki Masanori (Bacchus)
*Trombone: Sano Satoshi (Bacchus)
*Tenor Sax, Flute: Yoshida Osamu
*Turntable: D.J. Country
*Voice: Tsunku, One Coins
*Chorus: Petitmoni
*Dance Choreography: Natsu Mayumi
*Music Video: Miyasaka Mayumi
;Bicycle Daiseikou!
*Lyrics, Composition, Chorus: Tsunku
*Arrangement, Keyboards, Programming: Konishi Takao
*Manipulator: Katsuura Go
*Percussion: Yamaguchi Tomo
*Chorus: Petitmoni, MC Kids
==Performances==
===TV Performances===
*[2000.07.23] Hello! Morning (Episode #16)
*[2000.08.06] Hello! Morning (Episode #18)
*[2021.10.23] Miki Nonaka presents... Morning Musume '21 ~SONGS FOR YOU~ - Ikuta Erina, Ishida Ayumi, Oda Sakura 
===Concert Performances===
;Seishun Jidai 1.2.3!
*Hello! Project 2000 Atsumare! Summer Party
*Dream Live Pop Revue 2000
*Hello! Project 2001 Sugoizo! 21seiki
*Hello! Project 20th Anniversary!! Hello! Project 2018 WINTER ~PERFECT SCORE~ - Iikubo Haruna, Oda Sakura, Murota Mizuki, Miyazaki Yuka, Onoda Saori, Ichioka Reina (part of a medley)
;Baisekou Daiseikou!
*Morning Musume Concert Tour 2005 Natsu Aki "Baribari Kyoushitsu ~Koharu-chan Irasshai!~"
===Event Performances===
;Seishun Jidai 1.2.3!
*[2005.09.16] Morning Musume Fanclub Tour in Hong Kong 2005 - Yoshizawa Hitomi
*[2010.04.12] Yoshizawa Hitomi Special Live ~25kaime no "Arigatou"~ - Yoshizawa Hitomi
==Oricon Chart Positions==
Total Reported Sales: 484,160
==Trivia==
*An English cover of "Seishun Jidai 1.2.3!" was recorded by Irene Cara as "Our Youth 1.2.3!" for the album Cover Morning Musume Hello! Project!
==Videos==
==External Links==
*Discography: Hello! Project (archived), UP-FRONT WORKS, Tsunku.net
*Wikipedia: Japanese, English
*Lyrics: , 
cs:Seishun Jidai 1.2.3! / Bicycle Daiseikou!
da:Seishun Jidai 1.2.3! / Bicycle Daiseikou!
de:Seishun Jidai 1.2.3! / Bicycle Daiseikou!
es:Seishun Jidai 1.2.3! / Bicycle Daiseikou!
fr:Seishun Jidai 1.2.3! / Bicycle Daiseikou!
it:Seishun Jidai 1.2.3! / Bicycle Daiseikou!
ja:青春時代 1.2.3!/バイセコー大成功!
Category:2000 Singles
Category:2000 Number 1 Singles
Category:Petitmoni Singles
Category:2nd Generation Morning Musume Singles In
Category:3rd Generation Morning Musume Singles In
Category:4th Generation Morning Musume Singles In
Category:Double A-Side Single
Category:3 Members Line-Up
Category:Daily Number 1 Singles
Category:Highest Ranking Single
Category:Platinum Certification