Hane Aoba is a senior office worker who tries to help her younger colleague, Aki Kaminaga, get closer to Atsuto Sugaya, the girl he loves. However, Hane also has her own personal problems with her boyfriend, whom she is about to marry. While talking with Aki at a bar, she gets drunk to forget her problems, but that was a mistake because she ends up fucking to Aki. Although Hane asks him to forget what happened, Aki refuses and seduces her again in a meeting room.

Hane, despite feeling guilty, maintains an intimate relationship with Atsuto, even though she is engaged and has a close friendship with Aki, her coworker who loves Atsuto. Her relationship with her fiancé has become less frequent, while her physical connection with Atsuto has intensified. Hane tries to justify her actions, but she is fully aware that she is deeply involved with Atsuto both physically and emotionally.