"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.
as Miku Ohno
as Masao Kigawa
as Shun Masamiya
as Kenta Kashiwabara
as Ryosuke Kajii (agent)
as Tajio Hasegawa
as Taeko Ishinuki
as Kyoichi Kumada
as Kenichi Kamata
as Tomonori Sasaki
as Jukichi Matsuda
as Chief
as Atsushi Momose
as Chorus
as Chorus
as Director of record company
as Muneo Ohkouchi
as Akemi Ishinuki