Kenta Kanzaki is a classmate of Ichikawa Kyoutarou and Yamada Anna in Class 2-3, later continuing with them in Class 3-1. He maintains polite public manners, generally earning positive regard from classmates, yet openly dives into perverted discussions with close friends Adachi Shou and Chikara Ota. These talks frequently center on his unconventional preferences regarding girls, specifically expressing attraction to those differing from conventional beauty standards, such as overweight women or those with poor hygiene. This blunt honesty about his tastes earns him labels like "weirdo" or "ugly girl lover" from some peers. However, his openness about his preferences means most female classmates view him as harmless, comfortable that his affections are directed elsewhere.

His romantic focus is exclusively on Honoka Hara, a classmate whose chubby physique aligns with his stated preferences. Kanzaki frequently compliments Hara and openly praises her, though his attentiveness sometimes overwhelms her, causing uncertainty. He demonstrates protectiveness and jealousy over her, reacting negatively when Ichikawa unintentionally called her cute during White Day. Their relationship shifts from mutual interest to dating outside school, becoming an acknowledged couple. Ichikawa and Yamada indirectly facilitate their connection by distracting them with cat sounds in the library, allowing Kanzaki and Hara to bond. This relationship positions him as a foil to Ichikawa’s reserved romantic approach, contrasting Kanzaki’s tendency for excessive affection.

Academically and socially stable, Kanzaki ranked third in popularity during grade school. He serves as the catcher on the baseball team, necessitating his practical, short hairstyle. His role primarily provides comic relief through unfiltered comments on relationships and physical preferences, while also contributing to minor subplots involving class dynamics.