Takabe Tomohiro begins as a sexually inexperienced Japanese high school student. His classmate, Mina Hayase, unexpectedly proposes a purely physical relationship, inviting him to meet in the school nurse's office. He agrees, initiating a friends-with-benefits arrangement focused on gratification.

Guided by Mina, he quickly gains sexual confidence and becomes eager to experiment. Their encounters expand beyond the nurse's office to locations like classrooms, hallways, pool changing rooms, and cinema restrooms. His sexual relationships grow to include another classmate, Kaori Nonomiya, who observes Tomohiro with Mina and later participates with him, sometimes alongside Mina or the school nurse, Taeko Nonomiya. These interactions occasionally involve multi-partner scenarios, including threesomes.

Despite continuing these physical relationships, Tomohiro develops deeper romantic feelings specifically for Mina, desiring a connection beyond their sexual arrangement. This emotional shift creates tension, as Mina initially prefers maintaining a casual, non-romantic partnership, though she admits some fondness. His interactions with Nurse Taeko involve elements of compromised consent stemming from the power dynamic, though he does not actively protest.

Physically, Tomohiro is depicted with brown hair, and sources vary between brown eyes or purple eyes. His character development centers on his transition from sexual naivety to experienced confidence and the conflict between his physical engagements and his yearning for a genuine romantic relationship with Mina.