Yuko Tsudo, a science professor, flees her abusive ex-boyfriend Shuuichi Taki, a physical education teacher. Her escape culminates in a traumatic assault where Taki rapes her using a mummified demon's body, triggering a supernatural transformation that turns Yuko into a Lust Monster. This metamorphosis leaves her with an insatiable sexual appetite, yet her core motivation shifts to a supernatural imperative: locating a virgin woman capable of bearing and birthing her child. This quest defines her subsequent actions.

Yuko seeks emotional and physical comfort from her best friend and lover, Ayano. In one scene, Ayano invites Yuko into the shower, providing affectionate solace in the aftermath of her trauma. Ayano pursues an unspecified new research project, though Yuko’s potential involvement remains undocumented.

Her narrative unfolds exclusively within the first episode of a 1995 three-episode OVA series. Episodes two and three center on an unrelated storyline involving a teacher, his fiancée, and students during a mountain camping trip, devoid of Yuko’s presence. She appears in no other official media beyond this original OVA.