"GS Wonderland" is about the 1960's Group Sounds bands - A Japanese pop movement inspired by the Beatles and other mid-1960's Brit Pop. Three young men set out to start their own band "The Diamonds" when they are signed to a recording contract during their very first rehearsal. Things turn for the unexpected when their agent brings Mick (Chiaki Kuriyama) into the group as their keyboardist.
Chiaki Kuriyama
Takuya Ishida
Hiro Mizushima
Yōsuke Asari
Shinji Takeda
Sousuke Takaoka
Mana Mikura
Kendo Kobayashi
Ren Osugi
Tetta Sugimoto
Ittoku Kishibe
Jin Katagiri
Hajime Yamazaki
Yasuhito Hida
Toshifumi Muramatsu
Gota Watabe
Akinobu Shinoyama
Junpei Morita
Yoichi Nukumizu
Kana Mikura