Kazuhiko Hashimoto is the father of the film's protagonist, Tomie Hashimoto, and a widower living in a small, quiet town. He is a loving but emotionally distant parent, which creates a strained and tense atmosphere in the household he shares with his teenage daughter. His emotional distance leaves him in a state of profound loneliness, making him a deeply sad character who appears to be still mourning the loss of his wife.

The core of Kazuhiko's personality and motivation is rooted in an obsessive fixation from his past. Years before the events of the film, when he was a young man, he was involved in a tumultuous relationship with a beautiful and enigmatic woman named Tomie Kawakami. This relationship ended in her brutal murder. Despite this traumatic conclusion, Kazuhiko remained obsessed with her, and this obsession dictates the course of his life. He names his own daughter after his lost love, a decision that illustrates how completely the past haunts his present. He works at an industrial ice house, a facility that freezes objects to preserve them, a setting that becomes crucial to the film's climax.

Kazuhiko's role in the story is that of a man whose sanity is destroyed by the return of his obsessive love. When the supernatural Tomie Kawakami reappears and befriends his daughter, she recognizes Kazuhiko immediately and sets out to terrorize his family. She manipulates him, exploiting his unresolved feelings and attempting to convince him that his daughter is an obstacle to their reunion. For a time, it seems that his love for his daughter might overcome his obsession, as he ultimately chooses to murder Tomie with a meat cleaver rather than follow her command to kill Tomie Hashimoto.

However, this act of violence does not free him. When his daughter discovers Tomie's still-living, severed head and begins to care for it, the cycle of terror continues. Desperate for a permanent solution, Kazuhiko and his daughter freeze Tomie's regenerating body into a block of ice at his workplace. This plan becomes his final undoing. Unable to resist the frozen Tomie's seductive pleas and cries, Kazuhiko shatters the ice and frees her, completely succumbing to her power. In the film's most significant moment of development and betrayal, he makes a definitive choice. He locks his own human daughter inside the freezing room, leaving her to die, and walks away hand-in-hand with the monstrous Tomie Kawakami, choosing his destructive obsession over his family. By the end of the film, Kazuhiko has vanished, leaving his daughter to live alone with the chilling consequences of his actions.