A career woman named Kanna works at a major corporation and is well-liked by her colleagues due to her friendly demeanor and perpetual smile. However, she harbors a secret: she cannot maintain her sense of self without masturbating regularly, revealing herself to be a highly sexual individual with insatiable desires. One day, after missing the last train home, her younger coworker Ena shows up unannounced and ends up staying overnight... under the guise of an impromptu sleepover arranged by their boss. As they share a room, both women struggle to resist their urges until eventually, Kanna succumbs to temptation and begins pleasuring herself using some of Ena's personal belongings.
