Mr. and Mrs. Yamagishi move into the house of their father-in-law, Mineo, when their husband's employer goes bankrupt. Mineo gladly accepts them, but... Mineo has an inexhaustible libido even when he is old, and he is afraid that one day he will attack Kotone with a fit. However, if that's the case, she says, "It's better to take action than worry about her!" Kotone fell for Mineo's scheme, who was ostensibly good, and was violated. The unsatisfactory father-in-law's carnal desires can't end with just one time.
