From Nakama:
Kaibara Yousuke is a third-year college student looking for employment. During his second year, he'd immediately rebuffed his classmate Nakayamada Kazuki's offer: “Won't you have sex with me?” But that time, Kazuki's declaration of, “I could make you feel so good, you wouldn't be able to think of anything else,” was the beginning of their relationship. At first, Yousuke would shy away from sex, but he was healed by the unexpectedly tolerant Kazuki, and was gradually captivated.