Kyôsei shiiku: OL niku dorei.

Yumiko, an office worker, and Yota are engaged and living together. They've been dating for five years, but Yota is still head over heels in love with her. However, Yumiko is having an affair with a coworker. One day, after enjoying some passionate sex with her boss at a love hotel, she is photographed coming out of the hotel by Sato, a coworker.