Sumire is asked by her husband to show him what it's like being embraced by another man, while at the same time she pleads with her husband to watch her being with someone else. Two couples with opposing desires secretly join a "married mixer" without revealing their true relationships. As the night progresses, Sumi Kurokawa slips away to a hotel with Kana Morisawa's husband, Kenji. Meanwhile, Kana turns out to be an old acquaintance of Sumire's husband, Takashi. Their marital relationships gradually entangle in complex ways, as conflicting emotions and desires intertwine, driving the story into deeper, more intense territory.