Kataru Oizumi, a 13-year-old with perpetually flushed cheeks, sports messy brown hair and bright blue eyes. His stout frame is often clad in a white shirt layered beneath a green hoodie, paired with white shorts, green shoes, and a vibrant yellow backpack. Speaking with a soft, feminine lilt, he openly embraces crossdressing as both a pastime and tactical tool. His unwavering loyalty centers on his older brother Manabu, whom he fiercely protects—a devotion driving pivotal choices.

Early in his Battle Spirits career, Kataru’s inexperience led to a crushing defeat in the Hero Championship’s Gunslinger round, prompting him to abandon the game. Yet when Manabu fell into Mika’s trap, Kataru reclaimed his deck, mastering yellow burst strategies to triumph over Hajime. His arsenal, featuring The LightHero LunaArk-Kaguya, spirits like Pentan and Martiusagi, and magics such as Wing Boots and Moonlight Punish, became extensions of his resolve.

Post-Manabu’s graduation, Kataru pivoted to leadership, securing the student council presidency by besting Kimari in a heated election. He later confronted Chihiro Kusaka’s ex-fan club after they fixated on Manabu, deploying disguises to shield his brother—even donning a feminine guise to manipulate rival Tegamaru Tanashi.

Documented battles chart his evolution: setbacks temper his spirit, while victories against Hajime and Kimari mark his ascent. Balancing a sweet tooth and strategic crossdressing with tenacious loyalty, Kataru’s journey weaves playful eccentricity into a narrative of grit, proving resilience shapes both duelists and leaders.