Sentou Rezu Rensa Shuuchi 3: Iinari Ubu Musume o Riyou shita Imozuru-shiki Rezu Keikaku.

Exploiting the weakness of the daughter working at the family bathhouse, a perverted woman with a taste for younger girls launches a chain of lesbian encounters. She lures friends to the bathhouse and relentlessly drives them into female pleasure. The protagonist betrays her best friend, forcing her to join a scheme from which there is no escape—the "lesbian swamp." In the women's bath, erotic acts are repeated, and though the girls are bewildered, the seasoned techniques of older women lead them to complete submission.