There is an orphanage, a “school”, that raises girls with no relatives as weapons of war. Every day, students are taught to kill other people and take their lives without any mourning. One night, a fourteen-year-old Sheena, who had never been able to accept her circumstances, met a little girl named Mimi, covered in blood.

Fearful Sheena wished for peace, while cheerful Mimi always headed off to war with a smile on her face. However, after the encounter with Mimi, a girl who was rumored to be the school's secret weapon, Sheena's mind undergoes a change.

A story of two girls' innocent wishes, found in a world next to death.