Another of Ritsuka's classmates, Yayoi is depicted as socially awkward and struggling with low self-esteem. He harbors intense jealousy towards Ritsuka, fueled by his unrequited love for Yuiko. Despite confessing his feelings to her, Yayoi was rejected, with Yuiko claiming she only dates boys taller than her. However, this reason seems questionable given her obvious affection for Ritsuka, who is of similar height to Yayoi.
Though he feels envious of the close bond between Ritsuka and Yuiko, Yayoi finds some comfort in Ritsuka's insistence that their relationship is purely platonic. Determined not to give up on Yuiko, he makes a firm resolution and starts spending more time with her.
In the manga, Yayoi has a relatively minor role, appearing infrequently and having limited dialogue. In contrast, the anime expands his character significantly, using him to highlight the potential love triangle involving Yayoi, Yuiko, and Ritsuka, while also adding moments of comic relief to an otherwise dark narrative.










