Mofukuzuma: Unaji no nokoriga (1999)

Toru, an up-and-coming writer, learns from his former lover, Hitomi, that her husband, Toshihiko, has died; she suggests it might have been suicide. Ten years earlier, upon entering university, Toru had begun living with Toshihiko, a fellow student struggling with poverty. When he learned that Toshihiko was in love with Hitomi—a classmate from their seminar—Toru decided to help him win her over. However, circumstances led to Toru becoming intimate with Hitomi himself. Thus began his betrayal of Toshihiko...