As sadomasochistic yakuza enforcer Kakihara searches for his missing boss he comes across Ichi, a repressed and psychotic killer who may be able to inflict levels of pain that Kakihara has only dreamed of.

A masochistic mobster meets his match in the dark streets of Tokyo. His nemesis, Ichi, is a psychopathic killer with an unrelenting thirst for bloodshed. A horrifying secret burns in his mind, and his hands deal death without mercy. At last, the shrouds of mystery are parted to reveal the origin of the monster. The city will know its greatest fear at the unveiling of Ichi the Killer.

We follow Ichi during his high school years. Mr. Dai is the best fighter in school... whenever he fights Ichi is there and has a huge smile on his face. Mr. Dai thinks that Ichi is laughing at him but in fact he enjoys watching the violence that goes through the fights. Everyone is bullying, taunting and making fun of Ichi... even little kids from his karate class. Yet Ichi refuses to let go of his anger and fight others. Just when Mr. Dai is about to get Ichi, a new transfer student starts to make his own laws... by beating up everyone and breaking their bones! In a fight with the new student, Mr. Dai ends up on the ground, beaten and broken up from almost everywhere. It seems like this new guy wants to fight Ichi because supposedly he is the only one that could give him some challenge.