From wikipedia: Usagawa Rinne, a normal female high-school student, was spending happy days with her lover, Sakaki Guryuu. However, the peaceful days shattered suddenly, On the night of Sakaki's birthday, Sakaki witnessed Rinne get killed after her eyeball was gouged by a girl named "Gankyuu Eguriko" as well as witnessed Rinne revive as if nothing had happened. To the shocked Sakaki and confused Rinne, Gankyuu Eguriko speaks of an "Eden's Apple"... .