 After the breakup of Number Girl, Shutoku Mukai began touring solo under the moniker Mukai Shutoku Acoustic and Electric.Although initially performing new versions of Number Girl songs, he quickly developed many that would appear on Zazen Boys' first album.After touring through June 2003, Shutoku commissioned friend and former Number Girl drummer Ahito Inazawa, and after former Art-School bassist Hidekazu Hinata and guitarist Sō Yoshikane (formerly of Kicking the Lion) joined, the first incarnation of Zazen Boys was formed.