Has the world suddenly split into four? Keiwa Sakurai, Neon Kurama, Michinaga Azuma, and Tsumuri are flung into different worlds. And for some reason, a different Ace exists in each of the four worlds. The cause seems to be from the "World Doomsday Game" started by the staff from the future. In light of this crisis, the mysterious Cross Geats appears. Just what will happen to Ace and his friends?

The day before Tomoki’s wedding day, he is falsely accused of sexual harassment. Due to the false accusation, he loses his job and his fiance leaves him. Tomoki decides to kill himself. While standing on the ledge of a rooftop building, he sees a woman running toward him and screaming. She is attacked by a man with a knife. Tomoki becomes involved and gets stabbed by the man, but it turns out the attack was a staged event and Tomoki was not really stabbed. Tomoki learns that the staged event is called "enijya," which takes place upon a client's request. This is the first time he hears of eniya. Tomoki decides to hire Aika to take revenge on people who falsely accused him of sexual harassment.