-I ironically called a weak existence on the net that there is nothing to lose in isolation from society. Inori Takase, a high school girl who is the main character, was sexually assaulted by her withdrawal brother. It was Inori who lived hiding despair every day, but one day, a mysterious man, Nil, who suddenly appeared, kills Nori's older brother who is planning an indiscriminate murder. Inori freed from despair. But it finds an Invincible Person who has reached a dangerous waters like her brother and kills her before committing a crime ...