Ryuji Kita begins as a class bully, specifically targeting Riki, Momoko's twin brother. Driven by external pressures demanding academic and athletic excellence, he lashes out aggressively at peers. When Momoko, despite her disabilities, joins the same school during her challenging adjustment to mainstream education, Ryuji extends his bullying to her, revealing discomfort with her differences. This creates additional tension. However, Ryuji's character shows subtle development. His actions culminate in a significant decision signaling a shift from antagonism, with motivations conveyed through minimal dialogue and contextual cues. His arc resolves with an implied but meaningful change in behavior towards both siblings.