"He's cheating on me with my girlfriend," Yuuki's wife, Koyuki, is told. A few days after her husband's best friend, Shinji, makes the accusation, she receives a message that "the two are apparently meeting at a love hotel." Skeptical, she heads to the hotel and finds Yuuki leaning on a woman as he enters. Believing in her husband's innocence, Koyuki decides to cooperate with the investigation. She goes into the hotel again, only to hear suspicious noises coming from the rooms…