On the surface, Shiroishi is just a simple-minded guy who works at a metal shop and enjoys stopping by the red light district. At night Shiroishi becomes Ichi the Killer. When pushed to the brink emotionally, Ichi becomes a sadistic monster capable of ripping men to shreds. At first Ichi only kills when his guardian, Jijii, pushes him to. After awhile, fueled by an insatiable violent perversion, Ichi begins to grow in ways Jijii hadn't dared to hope.