After five years of marriage, Shizuko is having an affair with her childhood friend Ken, whom she met again at a class reunion. Ken was interested in Shizuko's big butt every time she lay on her body several times, but Shizuko stubbornly refused to have anal sex. One day, her classmate Fujiko finds out about her affair. Fujiko, who is also frustrated, calls her girlfriend Ken and falls asleep from her Shizuko with her boasted anal. The quagmire of the three people's relationship comes to a spectacular end on September 9th, the day of the Chrysanthemum Festival...
