While working on his graduation thesis at the library, Yoichi couldn't concentrate and couldn't stop his habitual urge to play with his nipples. Noticing his behavior, the librarian Kana became intrigued and reached out to touch his nipples herself. Surprised by his sensitive reaction, Kana couldn't resist and began teasing his nipples. The stimulation grew stronger and stronger until Yoichi reached climax. After that, regardless of who might see, Kana repeatedly played with his nipples, bringing him to orgasm over and over. Eventually, Yoichi grew addicted to the pleasure, unable to escape her grasp.