Mikado, a young man longing for something unusual in his life, moves to Ikebukuro at the invitation of his childhood friend Masaomi. Arriving in Tokyo, he begins his new life as a high school student, awed and mesmerized by the new world around him.

It is the Entrance Ceremony at Raira Academy, and the auditorium swells with a varied mix of emotions emitted from the students. Amidst all this is Rio Kamichika: a girl with a notably dark vibe following her.

Shizuo Heiwajima, also known as “the strongest man in Ikebukuro”, is a man who definitely relishes that title. Though he carries with him a high esteem, something is amiss. Lately he has been extremely short-tempered and does not know why.

Anri is targeted by the Slasher, but Kyohei’s gang moves to rescue her. Shizuo and Celty join in, and after defeating the Slasher, reveal his true identity. However, this moment of relief doesn’t last as Celty reads what has been posted in the chatroom.