Clamp is an all-female Japanese manga artist group that formed in the mid-1980s. It consists of leader Nanase Ohkawa who provides much of the storyline and screenplay for the group's works and adaptations. Clamp also includes three artists whose roles shift for each series: Mokona, Tsubaki Nekoi, and Satsuki Igarashi. Almost 100 million volumes of Clamp manga have been sold worldwide.