While the couple is living happily together, her unemployed brother suddenly comes to stay with them after being kicked out of his parents' house. After sending her husband off to work and finishing up the housework, Arisa indulges in masturbation in her room. Then her brother-in-law sees her and asks for sex just once, and out of embarrassment, she gives in. This act escalates from the next day, and she ends up making him give a blowjob to his friend and playing with him with a remote vibrator next to her husband, and even though she is troubled by it, she is drawn to her brother's carnal desires.