Risa broke up with her boyfriend six months ago and is now involved in a physical relationship with another man. He is her sex partner—a man older than her—and they first met back in high school, when he worked as a biology teacher. Risa doesn't have any particular hobbies and is just an ordinary, talkative girl. During her first year of high school, she suddenly fell in love with this biology teacher. He wasn't especially handsome, but looked younger than his mid-forties and had a slightly eccentric aura. In class, he seemed unmotivated, rarely made eye contact with students, and hardly spoke. At first, Risa saw him as just another dull middle-aged teacher. But one day, during a lesson, he began talking about science fiction—specifically, about cloned humans. The topic was strange, but his eyes burned with passion. Seeing that look, Risa became deeply intrigued by his inner world. Visiting the science club, she found herself captivated by the time spent alone talking with him. Due to their age difference and the teacher-student dynamic, she couldn't confess her feelings. Still, the two enjoyed their private conversations in the clubroom, maintaining a careful distance. Risa repeatedly dreamed of spending time alone with him. Yet, she never confessed on graduation day. Carrying that unresolved tension, she moved on to college and started dating a boyfriend closer to her age. After a three-year relationship, they broke up, and on a whim, she returned to her old high school. There, she found him still in the science clubroom, grading a pop quiz. Unable to hold back, she threw herself into his arms. Papers scattered across the floor, but neither cared—reigniting their relationship once again.