story is set in the year 311 of the Orbital Calendar, when humanity has
migrated to countless colony clusters in space. A space colony girl
named Akiha Shishido encounters a malevolent artificial intelligence
named Leopard that has been installed on a colony. Akiha is joined by
an Inter-Colony Police officer named Itsuki Kannagi, a taciturn young
girl named Honoka Kawai, and a robot named Imoko "Imo-chan" Shishidou.