While a member of Dutchman, Yamaguchi had been scouted and trained by Victor Entertainment. After they had managed to go through the audition process to perform at the Rising Sun Rock Festival, Yamaguchi sent his material with Sakanaction to his contact at Victor, which led to the band's debut through BabeStar. Originally the group featured three official members, after drummer Ejima had been added, but for the group's major label debut they officially promoted support members Kusakari and Okazaki. The band was unveiled as being on BabeStar's line-up in February 2007.
