Shoko, a married woman suffering from a sexless marriage, finds her heart stirred by the sounds of lovemaking coming from her new neighbors, the Arata couple, and begins masturbating every night. Constantly hearing their passionate moans, she imagines the husband as some wild, intensely sexual man—only to be shocked when she finally meets him and discovers he's actually a quiet, gentle man named Akira. This stark contrast fuels her secret fantasies about what he's really like in bed. One day, when Akira loses his keys and can't enter his home, Shoko kindly invites him into her house—but this small act of kindness will unravel desires she can no longer suppress.