After a date with his girlfriend who has a 5 PM curfew, he engages in an 'internal ejaculation sex act' with "her mother"—a sexual act involving creating a "girlfriend's younger sister." (Aoi Yurika ROE-543)

The other person's parents were very strict, with a curfew of 5 PM. Although I started dating Momoko through a friend's introduction, our dates were always limited to trendy cafes or art galleries. I hoped to take things further with Momoko, but I would always receive calls from her father urging me to come home. Until one day, I was invited to Momoko's home, where I met her mother, Ms. Yurika. Ms. Yurika was a mature and alluring beauty. However, when Ms. Yurika told me to break up with Momoko, I found myself unconsciously pushing her onto the bed… From then on, Ms. Yurika and I began to meet frequently in secret. Just a moment after Momoko left because of the 5 PM curfew…