Kōta Izumi, a boy scarred by the tragic deaths of his parents—the pro hero duo Water Hose, who perished saving civilians from Muscular—harbors deep trauma that hardens into a cynical worldview. Convinced heroes value duty over family and that hero-villain conflicts perpetuate suffering, he rejects hero society, quirks, and aspiring heroes like Izuku Midoriya, even lashing out violently during their first meeting. When Muscular targets him at a training camp, Izuku risks life-threatening injury to shield him. Kōta’s resolve fractures upon witnessing Izuku’s unwavering resolve and recalling Mandalay’s counsel about meeting a hero willing to die for him. He overcomes his aversion to quirks, employing his Water Gun to distract Muscular—a pivotal act marking his emotional turning point. Inspired by Izuku’s selflessness, he begins embracing heroic ideals, later sending a heartfelt letter and adopting red sneakers mirroring Izuku’s as a tribute. Amid societal collapse triggered by rampant villainy, Kōta demonstrates newfound courage by publicly defending Izuku during U.A. High’s refugee crisis, crediting him as the catalyst for his transformation. His journey from isolation to solidarity highlights a commitment to heroism’s communal spirit. This evolution culminates in his enrollment at U.A.’s hero course years later, determined to honor his parents’ legacy by following Izuku’s path. Kōta’s quirk, Water Gun, enables him to generate and project pressurized streams from his palms. Once stifled by his disdain for heroics, its strategic use against Muscular reveals untapped potential. His appearance features short black hair, a crimson cap with gold-tipped horns, and a wardrobe shifting from casual wear to U.A.’s uniform post-enrollment. Relationships with guardian Mandalay and peers like Minoru Mineta—whom he publicly admonishes for lewd conduct—underscore his moral integrity and burgeoning responsibility. Thematically tied to resilience via his name’s aquatic roots (“flood,” “sparkling water”), Kōta’s arc mirrors narratives like *Naruto*’s Inari: parental loss, initial hostility toward a protagonist, and redemption through a hero’s influence, weaving a tale of renewal through adversity.