People throughout the city speak of an urban legend known as the “Headless Rider”. A surprising number of people have personally witnessed it speeding down the streets on a jet-black motorbike with no license plate.

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's missing friend, the Dullahan, the girl with the scar on her neck, Yagiri Pharmaceuticals, the kidnappings, and the Dollars... little by little, the pieces begin to fall into place.

Anri is attacked by the Slasher. The same night, the user Saika appears in the chatroom, and posts a puzzling message. Mikado, worried about rumors that the Slashers are the Dollars, decides to cooperate with Celty.

After doing some investigating, Masaomi starts to suspect that the remnants of the Blue Squares, a gang that he once fought, have slipped into the Dollars. He decides to visit Kyohei’s gang to learn the truth.