Tomie's cells are programmed to divide. Even if she stayed with one man, she would eventually "split" into two Tomies, who would then hate and attempt to kill each other.
It takes the core concept of the character—a creature defined by her ego and her ability to regenerate—and twists it into a story about obsession, aging, and the true meaning of "eternal love." tomie wants to get married wiki
Every man who falls for Tomie eventually feels an uncontrollable urge to kill and dismember her. No marriage can survive a homicide. Tomie's cells are programmed to divide