OBA-321 A married woman named Yagi Michika invites her lover to her home and indulges in sex while her husband is away.

This year's popular idol group 'Puripuri Princess Z' concert. Michika and her son and husband decided to go. The night before, while looking forward to the concert, Michika and her son were dancing to Puripuri Princess Z's hit song. At that moment, Michika received a phone call. It was from Kenichi, a younger sex friend she met at work. Then on the day of the concert, Michika feigned illness to break her promise with her son and husband, bringing Kenichi into their empty home…