Color bottle is a Japanese rock band formed in 2004. The band consists of 4 members: ?????? (Masayuki Takemori) - vocals ?????(Akira Watanabe) - guitar ?????(Taichi Akimoto) - bass ??“Z”??(Junji Okawa) - drums They sing the song "???" (Aoi hana) which is the opening theme for the anime Casshern Sins.