Born and raised in a rural Hiroshima town, Haruto Kirishima once encountered a lost Yuzuki Eba during a childhood summer festival, comforting her and suggesting she seek him if troubled again—though he later forgot this meeting. Entering middle school, he developed an unspoken affection for classmate Nanami Kanzaki that persisted into high school. Standing 175 cm with a normal build, brown hair, and dark-blue eyes, he was initially reserved and shy yet stubborn in affection, displaying kindness and responsibility while often averting his gaze in intimate or misunderstood situations. His cooking skills, refined through family meals and part-time restaurant work, led him to join the school cooking club—partly hoping Nanami would join.

When Yuzuki moved from Tokyo to live with his family, Haruto reacted with irritation and failed to recognize her initially. Despite this, he grew protective, forming a close friendship. Yuzuki helped him become more outgoing, enabling his confession to Nanami, who later rejected him after he repeatedly prioritized Yuzuki’s needs over their plans—including missing a date to assist Yuzuki with Tokyo family issues. Nanami confirmed her rejection stemmed from Haruto’s unresolved feelings for Yuzuki. After Yuzuki returned to Tokyo, Haruto confessed his love, starting a long-distance relationship that faltered when she abruptly cut contact. Discovering a farewell letter in her gift—indicating she had a new boyfriend—Haruto fell into deep depression. Suspecting trouble, he transferred to a Tokyo high school, learning Yuzuki dated Kyousuke Kazama, who had under a year to live due to terminal illness. Haruto declared "war" on Kazama for Yuzuki’s affections, preferring open competition over secret resentment. Kazama initially survived risky surgery but died shortly after from postoperative stress.

Following Kazama’s funeral, Haruto and Yuzuki parted permanently. Months later, Haruto accepted a confession from neighbor and friend Asuka Mishima after her ultimatum. They dated for a year and a half until repeated chance encounters with Yuzuki rekindled Haruto’s feelings. Acknowledging this to Asuka caused their breakup and cost him several friendships. Haruto and Yuzuki reconciled, eventually cohabiting in Tokyo despite her father’s initial opposition. During college, they balanced part-time jobs and new acquaintances, strengthening their bond. Post-graduation, career assignments separated them: Haruto worked in Kōchi while Yuzuki taught in Tokyo. Long-distance strain led to their breakup after Yuzuki collapsed from overwork. Years later, Haruto developed the successful beverage "Yuzu no Hana" and transferred back to Tokyo, reuniting with Yuzuki under cherry blossoms as promised. They married, had a son named Daiki, and opened Kirishima Restaurant. A decade later, they returned to Hiroshima, where Haruto ran the restaurant with Yuzuki assisting during school breaks.