Tomohiro Takabe starts as an inexperienced high school student. His routine life shifts dramatically when classmate Mina Hayase unexpectedly proposes a physical relationship, leading to their first sexual encounter in the school nurse's office. This marks his entry into casual intimacy.

Initially surprised by Mina's forwardness, he adjusts to their arrangement as "sexfriends," frequently using the nurse's office provided by Nurse Taeko Nonomiya. Despite the purely physical nature of their relationship, he develops genuine romantic feelings for Mina, conflicting with her preference for keeping things casual.

His relationships broaden when classmate Kaori Nonomiya observes him with Mina and later participates in their sexual activities, including threesomes. He also engages individually with Kaori and with Nurse Taeko Nonomiya, revealed as Kaori's sister. Through these encounters, he evolves from passivity to greater confidence, actively participating in and sometimes initiating sexual scenarios involving role-play and toys during group activities.

He has brown hair and brown eyes.