Mirio Togata

Mirio Togata (通形ミリオ) is a third-year student at U.A. High and is part of The Big Three. Before Izuku Midoriya, Mirio was one of the top candidates for All Might's successor and inheritor of One For All.

Appearance
Mirio is a muscular young man with scars on his arms. His face is drawn in a simplistic, cartoony way and his hair is arranged in a cowlick.

His Hero costume consists of a large mask which covers the space around his eyes and ears, a plated shirt with the number one million (1000000) across his chest, with black pants and boots. He also sports a floor length dark cape attached from the chest which also features a hood.

Personality
Mirio is goofy and energetic, with some peculiar habits. He is almost always smiling. Though optimistic, he does not let his ideals blind him, and is always looking for ways to improve his skills. He is very devoted to becoming a hero and is the top candidate for No. 1 Hero after he graduates, even surpassing many of the pros. Though he does not make the best grades in school, he is extremely dedicated and worked many hours to perfect the use of his Quirk for combat, and thus is ranked among the top 3 students at U.A.

History
According to Nejire Hadou, Mirio once struggled a lot at U.A. High (even showcasing poor results in an edition of the Sports Festival); however, he would turn around his situation by devoting himself as an intern under a hero named Sir and having his abilities cultivated during his internship, eventually becoming a major contender for the number one rank, above several pro heroes.

Quirk and Abilities
Permeation: Mirio's Quirk allows him to become intangible, letting him travel through solid walls and the ground, while letting enemy attacks slip through him. However, when he becomes intangible his clothes slips through him, leaving him nude. By activating his Quirk, he can slip through the floor into the ground, then reposition himself and deactivate to cause himself to shoot back out of the ground in a different spot. However while fully intangible, he can no longer see, hear, or breathe, and can only experience a falling sensation.
 * Blinder Touch: Eyeball Crush: A feint where Mirio pretends to poke an opponent in the eye while his arm is intangible, distracting them long enough to deliver an actual blow to their stomach.

Overall Abilities: Mirio is extremely powerful, showcasing incredible mastery over his Quirk, such that the students of Class-A thought him to be invincible. He is considered a top contender for the rank of number one hero, previously held by All Might and currently occupied by Endeavor. He is likely the strongest of the Big Three, and is able to beat half of Class 1-A in less than six seconds.

Enhanced Strength: Mirio seems to possess a good deal of physical strength, enough to knock out a person and crush floors easily. This appears to come from his well-trained muscular body.

Enhanced Speed: Mirio is also incredibly fast, taking out Class-A very quickly and with absolute ease. This, combined with his strength and the rapid relocation aspect of his Quirk makes him incredibly formidable in combat.

Tamaki Amajiki
Mirio, Tamaki, and Nejire have known one another over the three years of their studies at UA. During their years of study, Tamaki and Nejire have seen the endeavors Mirio had to go through and understood what he went through to become stronger and the technique Mirio created in the process.

Tamaki commented how Mirio was always strong since he was a child. This leaves the possibility that the two have known one another since childhood.

Nejire Hadou
Like with Tamaki, Nejire and Mirio have spent three years together studying at UA becoming good friends with one another. During their years of study, she and Tamaki have seen the endeavors Mirio had to go through and understood what he went through to become stronger.

She and Mirio have similar energetic personalities which conflicts with Nejire's talkative attitude, much to her chagrin. However, this similar personality also make it easier for both of them to talk with one another, unlike Tamaki's quiet nature.

Izuku Midoriya
Prior to the Big Three's introduction, Mirio went out of his way to talk with Izuku. He is rather friendly to Izuku, who at first found Mirio to be strange. After witnessing Mirio's power and technique, Izuku grew to admire Mirio, even thinking that he already seems to be like a pro hero in the way he talks.

Mirio seems to hold him in high regard, despite only having just met and Izuku being a first-year. When All Might asked if Izuku was suited to an internship with Nighteye, Mirio said that he had been thinking Nighteye would like Izuku from the very beginning. Mirio is eager to help Izuku succeed, offering lots of tips and bits of advice before introducing him to Nighteye.

It is currently unconfirmed how much Mirio knows about Izuku and One for All. He seemed certain that Izuku would meet Sir, All Might's former sidekick, and did not look surprised when the retired No. 1 hero summoned him and Izuku to ask him to intercede for the latter. Mirio also took notice of the scars on Izuku's arms, which were caused by One for All.

Toshinori Yagi
Mirio respects and admires All Might greatly, even after the latter lost his powers, claiming he could not help being happy after being called in by him. Some of his most outlandish behaviours are similar to the energy of All Might's public persona. It is unknown if Mirio is aware that he was the top prospective candidate for One for All.

Sir Nighteye
Mirio works under him for his internship. Sir Nighteye views him as a full-fledged student with an immense potential, making him believe that Mirio deserves to inherit One For All.

Trivia

 * Mirio's Hero name is "Lemillion", which according to him sounds like the rock band Remioromen, which is a reference an actual Japanese Rock Band.
 * According to Mirio, he named himself Lemillion because he wants to save a "million" people.