Based on the original manga, 1-ICHI is a prequel to Takashi Miike's ICHI THE KILLER and a film on its own. Nao Omori reprise the role of Ichi, who we follow 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 (Kôji Chihara) 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 broked 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.