Takuya's father has died in an accident while carrying out research. Concerned for his young stepmother, Ryumi, Takuya follows her to a place called Ken point, where he secretly watches her and her best friend, Mitsuki, from behind a rock. A sudden burst of light takes the form of an otherworldly beautiful woman, who places a ring on his finger. That ring links Takuya to other realities, and with it he begins traveling into a parallel world. The four-episode adult OVA blends science fiction with explicit content.