A close friend of Mami's named Rena introduces her to a new app that promises exciting sexual encounters. After some hesitation, Rena decides to give it a try and soon meets a young student named Shinji through the app. He's submissive, honest, and incredibly cute. As they begin their journey together, Rena discovers the thrill of dominating someone younger than herself. She slowly becomes more and more immersed in this dangerous game of seduction... *The contents may vary depending on the distribution method.