Minamoto Kou attends Kamome Academy as a middle school student and inherits his lineage from the prestigious Minamoto Clan, a family of exorcists famed for defeating entities like Shuten-doji. Positioned as the second son between stern elder brother Teru and younger sister Tiara, he initially pursues his family’s mission to exorcise Hanako, the school’s seventh mystery. However, his worldview transforms through alliances with Hanako and Nene Yashiro, challenging his clan’s doctrine that all supernaturals are malicious. Kou sports spiky blond hair, light blue eyes, and a red traffic-safety earring that doubles as a charm, inspiring nicknames like "Traffic-Safety Earring Boy." His unbuttoned uniform, striped tie, and red sweatband contrast with his inherited exorcist tool, Raiteijou—a spirit staff masquerading as a black umbrella, its lightning powers partially sealed by Hanako. Supernatural encounters sometimes temporarily morph him into an adult form mirroring Teru, complicating interactions with peers. Cheerful and blunt, Kou exudes a mischievous energy, acting impulsively yet maintaining polite manners and unwavering moral integrity. He matures into a loyal friend who defends harmless supernaturals, clashing with Teru over their family’s rigid principles. His determination to judge spirits case-by-case fuels both growth and friction, as he balances exorcist duties with empathy. Gifted with supernatural perception, Kou wields Raiteijou to channel lightning, though inexperience leads to accidental shocks. The staff’s sealed state forces him to rely on raw ingenuity during battles. Despite setbacks, he relentlessly trains to protect others and forge his own exorcist identity beyond familial legacy. Key relationships shape his journey: a rivalry-turned-alliance with Hanako, whom he vows to judge independently; a supportive bond with Nene, transitioning from crush to steadfast camaraderie; and conflicted attempts to aid Mitsuba, a spirit with opposing traits. Pivotal arcs see him shielding Hanako from Teru’s wrath, grappling with altered timelines, and confronting self-doubt while upholding his compassionate resolve. Notable trivia includes culinary skills honed from housework responsibilities, a sweet tooth for sweet potato jellies, and a methodical approach to peeling oranges. His earring’s kanji subtly nods to his name through wordplay, while his voice actor’s real-life friendship with Mitsuba’s actor echoes their characters’ dynamic.