Chisato, a mom friend from the same neighborhood, is a sexually frustrated big-breasted mom... Yukie is always aroused by Chisato's big breasts. "Am I a lesbian?" Yukie worries, and one day Chisato comes to her for advice about her sex life, but Yukie confesses that she is also attracted to Chisato. She invites the confused Chisato to have sex with her. The two escalate into a lustful mature lesbian relationship that can't stop at the pleasure they've never experienced before!