sentences:  The event traumatized Toma so much that Yoyu, a friend of the family, seals the memories regarding the event.He was under the care of Yoyu for half a year and is currently living with Mikage and Fusa.Concerned over Toma's overconfidence and inexperience with Horrors, Mikage and Fusa bring him to an abandoned building to help them in exterminating the Horrors living that.