Madonna exclusive, active receptionist, first drama series!! She was supposed to practice sex with her daughter's virgin boyfriend, but she was awakened by a runaway locomotive that never stopped no matter how many times she came!! "Even though she was a virgin, I was underestimating the sexual desires of young people..."

Satsuki is happy that her daughter has a boyfriend. One day, I forgot something and went back to my house and my daughter was bringing her boyfriend, Okamoto, with me. When I looked into the room to find out what was going on, the two of them were awkward and didn't go well after their first sex. Isatsuki, who wants to support her daughter's love, decides to become a training tool to help Okamoto gain confidence. However, Satsuki's voluptuous body makes Okamoto even more excited than he imagined. It was supposed to be just a dry humping, but it crossed the forbidden line, and the hard-earned cock lost control like a runaway locomotive.