Because her husband had to go on a business trip, Hikari hadn't had sex for a long time. Today, Hikari's daughter brought her boyfriend home. Witnessing her daughter and boyfriend having sex made Hikari feel extremely radiant. A few days later, because the school organized a trip, her daughter would go for about three days. Yudzuru forgot to charge it, so she came to look for him, she helped him find it, but accidentally revealed his underwear, which made Yudzuru unable to restrain himself. "I'm always paying attention to you! I can't stand it anymore!" Hikari tried to resist and reminded herself that she couldn't do this, but deep down she knew that she had always had a desire for sex, wanting to be satisfied by her daughter's boyfriend. When she was made to orgasm by Yudzuru, she decided to give in to her feelings. After this time, both Hikari and Yudzuru couldn't forget each other's bodies. The two secretly date and have sex every time Hikari's daughter is absent...