Mirio Togata, known as the hero Lemillion, is a third-year U.A. High School student leading the Big Three alongside Tamaki Amajiki and Nejire Hado. His hero name reflects his goal to save one million people. His appearance features a muscular build, blond hair with a cowlick, and simple blue oval-shaped eyes without visible sclera. Scars mark his lower arms. His hero costume includes a white bodysuit displaying "1000000" on the chest, dark blue pants, red gloves, a cape, and a visor; its special fibers, made from his hair, allow it to phase with him. He previously wore his hair in a ponytail before cutting it short. Post-graduation, his hair grows longer with shaved sides forming a spiraling pompadour, and his updated costume adds a chest plate, elongated gloves with angular patterns, and boots featuring track-inspired "zero" and "one" motifs. Mirio balances an exuberant, goofy personality with deep resolve. He often smiles, uses humor, and performs lighthearted pranks, sometimes employing his buttocks as a distraction. He remains polite, especially when apologizing for accidental nudity caused by his Quirk. Underlying his cheerfulness is profound determination, sparked after a Pro Hero saved him from drowning as a child. He trained relentlessly to master his initially troublesome Quirk, Permeation, rising from being "dead last" in his cohort. His mantra, "A world without smiles and humor has no bright future," underscores his optimism. He exhibits exceptional emotional control, prioritizing missions over feelings, like restraining Izuku Midoriya during an undercover operation. Guilt over Eri's suffering fueled his vow to protect her. He confronts villains like Overhaul calmly, fighting quirkless to shield her. His Quirk, Permeation, grants intangibility, letting him phase through matter. Activation disables his senses except the feeling of falling and prevents breathing; deactivating while phased ejects him solidly. He mastered it for high-speed repositioning and evasion. His combat integrates super moves: "Blinder Touch: Eyeball Crush" (an intangible eye-poke feint followed by a solar plexus strike) and "Phantom Menace" (a rapid combo using repeated phasing from multiple angles). Even quirkless, his physical strength, speed, and durability are formidable, demonstrated by defeating 18 Class 1-A students swiftly and fighting Overhaul's group single-handedly while protecting Eri. His tactical prediction allowed him to battle quirkless against Overhaul for five minutes after taking a Quirk-Destroying bullet meant for Eri. Key events define his journey. During the Shie Hassaikai Raid, he sacrificed his Quirk to save Eri. Despite losing his mentor Sir Nighteye and his abilities, he remained steadfast, refusing Izuku's offer of One For All and accepting his quirkless state. Post-raid, he bonded protectively with Eri, aiding her emotional recovery. Six months later, Eri mastered her Rewind Quirk and restored his Permeation. He immediately rejoined battles, repelling Near High-End Nomus in the Paranormal Liberation War. In the Final War, he served as a communication relay and combatant, helping hold off Tomura Shigaraki. Post-graduation, he rises to become Japan's No. 1 Pro Hero by age 26. Mirio fosters cooperative relationships. He mentors younger students like Izuku and acts as a "big brother" to Eri, ensuring her safety and helping her smile. Within the Big Three, he supports Tamaki and Nejire, boosting their confidence during missions. His interactions consistently emphasize teamwork over individual glory.