Splashing Blood and Steam, Inside a Shower of Love Pt 2 Episode 10

The hot springs manager has been attacked, and Sunako decides that she cannot pass up the opportunity to snoop around a real crime scene. However, the true culprit resents not only Sunako snooping around, but also her being accompanied by the four bishōnen. It turns out that the wife of the manager is responsible, plotting to kill Sunako by burning her alive in the storage room, by which Kyohei is able to rescue her out of. When they confront the wife of the manager, who insults Sunako's appearance, Kyohei states they have kissed.