Mizuki is a housekeeper who is very dedicated to her work and has a serious personality. One morning, while serving tea to her master, she accidentally spills the tea on his crotch. In a panic, Mizuki thinks he may have been burned, so she takes off his trousers and underwear and starts to cool his crotch. The master then thinks that he can use her serious personality for something lewd, so together with his son, he makes various lewd requests of the housekeeper. The housekeeper says "Yes, I understand" to all of their requests and fulfills the requests of her and her son.