Clamp (クランプ Kuranpu?), is an all-female Japanese manga artist group that formed in the mid-1980s. It consists of leader Nanase Ohkawa (大川 七瀬 Ōkawa Nanase?), who provides much of the storyline and screenplay for the group's works and adaptations[citation needed], and three artists whose roles shift for each series: Mokona (もこな Mokona?), Tsubaki Nekoi (猫井 椿 Nekoi Tsubaki?), and Satsuki Igarashi (いがらし 寒月 Igarashi Satsuki?). Almost 100 million Clamp tankōbon copies have been sold worldwide as of October 2007.