Mirio Togata attends U.A. High School as a third-year in Class 3-B and leads the elite Big Three alongside Tamaki Amajiki and Nejire Hado. His hero name, Lemillion, stems from his ambition to save one million people, recognizing he cannot rescue everyone but relentlessly pursuing that goal. Born with the Quirk Permeation, Mirio phases through solid matter by turning intangible. This ability initially caused accidental nudity and sensory deprivation as light and sound passed through him during activation. His father warned against a hero career due to the Quirk's limitations yet supported his determination. A childhood rescue from drowning by an unnamed Pro Hero cemented his resolve to become a hero who delivers hope. During middle school, he befriended Tamaki Amajiki, forming a lifelong bond of mutual inspiration. Under Sir Nighteye's mentorship, Mirio mastered Permeation through relentless training, evolving it into a formidable asset that earned him recognition as U.A.'s strongest student and a candidate to inherit One For All before Izuku Midoriya's selection. Mirio possesses a tall, muscular build with scars on his lower arms, simplistic blue eyes lacking visible sclera, and a rounded nose. His blond hair sports a cowlick, previously worn in a ponytail. His hero costume—woven from special fibers derived from his hair to phase with his Quirk—includes a white bodysuit marked "1000000," dark blue pants, red gloves, a cape, and a rarely worn visor. Post-graduation, his costume incorporated angular patterns and track-inspired soles, while his hair grew into a spiraling pompadour. Energetic and optimistic, Mirio radiates goofy humor, punctuating battles with his signature "POWERRRR!" cry. He uplifts others through comedy, such as using his buttocks as a puppet to cheer Eri. Beneath this levity lies profound bravery, emotional control, and tactical brilliance, exemplified when he maintained cheerful composure undercover with yakuza leader Overhaul. His selflessness defines him: during the Shie Hassaikai raid, he shielded Eri from Overhaul and lost his Quirk to a Quirk-Destroying bullet. Despite this sacrifice and Sir Nighteye's death, he declined Izuku's offer of One For All, trusting Eri could restore his power. He became Eri's protective guardian, aiding her Quirk training. Mirio's combat prowess emerged from rigorous drills. He honed Permeation for precision strikes like the "Blinder Touch Eyeball Crush"—feinting an eye jab to gut-punch—and "Phantom Menace," rapidly phasing through surfaces to assault from multiple angles. Even Quirkless, he withstood Overhaul for five minutes using raw strength and predictive skill. His capabilities include enhanced strength (shattering floors with punches), speed (defeating 18 Class 1-A students in seconds), and durability (enduring reconstructed debris attacks). After Eri restored his Quirk, he repelled Near High-End Nomus in the Paranormal Liberation War and helped restrain Tomura Shigaraki in the Final War. Key relationships shape his path. Tamaki Amajiki, his closest friend, sees Mirio as a sun-like inspiration driving their shared heroism. Nejire Hado bonds with him over exuberant energy, fighting alongside him post-Quirk restoration. He revered Sir Nighteye as a mentor, embracing his final prophecy of Mirio becoming a great hero. His dynamic with Izuku Midoriya blends mentorship and mutual respect; he refused Izuku's offer of One For All to forge his own legacy. He emulates All Might's charismatic heroism. Post-Final War, Mirio graduated U.A. and became a Pro Hero. Eight years later, he ascended to Japan's No. 1 Hero rank, surpassing peers like Bakugo and Shoto Todoroki through charisma, rescue achievements, and refined abilities.