Keiichi Kanejo, the older brother of Kyoka Kanejo, hails from immense wealth and attends Harvard Business School. His exceptional attractiveness makes him the object of infatuation for nearly every woman he meets, including noblewomen. Despite this perceived perfection and status, Keiichi remains a virgin, partly due to Kyoka secretly eliminating potential romantic rivals to maintain her obsessive attachment.

During a visit to Japan, Keiichi becomes intrigued by Yamada precisely because she is the first woman who does not fawn over him. Her indifference sparks his interest, leading him to actively pursue her. He directly asks her out but faces rejection; however, he persists, refusing to accept her refusal. This rejection intensifies his fixation, contrasting sharply with his usual experiences.

Later, Keiichi returns to Japan as a guest English teacher at Yamada's high school, further intertwining himself in her life. His romantic pursuit of Yamada continues, driven by her unique resistance to his charms. Throughout the series, their interactions highlight his inexperience in genuine emotional connections, as Kyoka's interference previously obstructed any relationships. His storyline concludes without reciprocation from Yamada, leaving his feelings unresolved.