Yui, a married woman who attended her school reunion, found herself unable to return home due to a car breakdown. Her ex-boyfriend Satoru offered to let her stay over out of concern, but she lied to her husband that she was staying at a 'female friend's' house to avoid unnecessary worry. Overwhelmed by guilt, she went to sleep. In the room with a broken air conditioner, the two continued having sex driven by instinct.
