[It’s a violent yuri that has people dying and killing] “I’ll fall down to hell. If that would save the child, that’s nothing but a cheap price.” Mido Sayoko, a female high school student who is not good at sports, studying and personal relationships. One night, she was selected by future people from the 27th century as an experimental body called [Opponent], as teaching materials for a university class. Special abilities were given to kill each other, but Sayoko’s ability were neither nullification nor elimination ability, it was really [Nothing]. Sayoko struggles just to survive every night with there having no way to fight against an ability person. However, after a certain night, she decided to fight. …To kill all opponents, including herself, except for one person.