Manji is a college entrance exam ronin student living alone in an apartment without a bath. One day, his sister-in-law Harumi runs away from home and moves into Manji's room. Ignoring Manji's confusion, Harumi heads to the public bath. Harumi, who was a regular customer, begs the owner, Sasagi, to let her take a bath before the bathhouse opens. However, after being at the bathhouse for the first time in a while, Harumi gets too excited and becomes overheated and unable to move. Manji rushes to help, but some female customers come in...