|Age||30s or 40s|
Heihachiro Ikuma is a lover of Shizuko Yamamura and a stepfather of Sadako. n the books, he had an affair with Shizuko whilst working as a professor at Tokyo University. He gained tuberculosis after Shizuko's suicide whilst to activate possible psychic powers of his own and was hospitalsied for many years. In the films, he cared for Sadako but locked her evil twin away for years. He eventually tossed her down the well after both girls reunited and killed numerous people. He died shortly after.
Ikuma's history was unknown.
Ikuma is intrigued by the psychic abilities of his patient (Shizuko Yamamura), a fascination that soon has the married Ikuma entering into an affair with her. When Shizuko conceives, she returns to Oshima in order to spare Ikuma from possible scandal. Later that year, Sadako is born. Shizuko entrusts the child to her grandmother to return to Tokyo and reunite with her lover.
Ikuma died with a decease.
- Nagao Jotaro was replaced by Ikuma. During, he killed Sadako.