Yuji has just returned from a trip with his father. What he saw was a lascivious spectacle of his brother and mother-in-law Riho, who remained at home, engrossed in each other. Having secret feelings for Riho, he becomes jealous and presses Riho for a relationship. Riho reluctantly accepts him on a one-time basis, but she continues to be asked for her body all over her house.
