Mitsuru Hanazono attends middle school as a classmate of Tomoya Mizuhara. He often fixates on girls and envies Tomoya's frequent proximity to attractive older girls, especially Ichika Mizuhara and her friends. Mitsuru nonetheless displays loyalty by defending Tomoya during Kouki Hayasaka's harassment.

He possesses a pronounced sister complex, openly favoring attractive older sisters. Mitsuru regards Ichika as an ideal older sister figure, contrasting sharply with Tomoya's perspective. This attraction includes Ichika's friends Ruri Hayasaka and Marina Mochizuki, intensifying his envy when they visit Tomoya's home. Convinced of his own irresistibility, Mitsuru confidently pursues older girls without concern for embarrassment. His social interactions consistently prioritize Ichika and her circle over female peers his own age.