Ayana Yukihira is a second-year in high school, and after her parents’ divorce, she’s looking for a new start in an apartment of her own. But when she receives the keys, she finds another girl already there—fresh out of the bath! Due to an administrative error, the apartment was also rented out to Yuu Fukami, one of Ayana’s classmates at her new school. But instead of forcing Ayana to find another place to live, Yuu invites Ayana to share the lease as a roommate. As it turns out, the girls also share a mutual attraction that grows with every touch, every passing day…until they’re virtually drowning in it.