Group Tamashii (グループ魂, Gurūpu Tamashii) is a Japanese rock band. It was started by actors in a theatrical company called "Otona Keikaku" (Project Adult) in 1995. Its original members were Hakai (Sadao Abe), Boudou (Kankuro Kudo), and Baito Kun (Seminosuke Murasugi). When it started, the group was just a group of comedians using the guitar. The members perform in many theaters, and also at Shōten. In 1997, bass, guitar, and drum players join and became a band.