Beautiful housewife Aki, having moved to a new city due to her husband's job transfer, suffers from loneliness as she rarely gets to spend time with him. One day, after yet another day without seeing her busy husband, she calls him and jokingly says, "I might start cheating on you!" before abruptly hanging up. The person who received that call was her husband's boss, Oshima. Noticing that his subordinate's wife is struggling with loneliness and sexual frustration, he decides to visit her at home, claiming he wants to help. From this moment on, a dramatic story of infidelity begins to unfold.