Izuku is a very timid, reserved, and polite boy, frequently overreacting to abnormal situations with exaggerated expressions. Due to yeаrs of being looked down on by Katsuki for lacking a Quirk, he is initially portrayed as insecure, tearful, vulnerable, and non-expressive. These traits are especially present around Katsuki, who also constantly harangued him for his aspirations to become a hero. However, after being accepted into U.A., making new friends, and facing Katsuki during the Battle Trial Arc, Izuku gradually matures into a more confident and brave person who's always eager to prove his worth as a hero, eventually developing strong leadership skills, which combined with his passion and strategic abilities, have turned him into a central figure within Class 1-A alongside Katsuki.

Izuku is a quite diligent and strong-willed student, being extremely (and sometimes scarily) enthusiastic about topics related to heroes. His dream drives him to write down notes about everything he learns in regards to heroes' Quirks and fighting capabilities. Thanks to this practice, Izuku has developed a great analytical mind and can form complex battle plans in a few seconds, factoring in the best ways he can utilize the Quirks of allies and enemies alike for his own advantage.

Izuku externalizes his observations through endless mumbling, a habit that annoys or creeps out his peers. Izuku often writes down his observations in a variety of notebooks he titles as Hero Analysis for the Future, checking on them regularly during school activities or at night.

Izuku is caring and emotional, never hesitating to help or rescue someone in danger, even if he knows that he might not be strong or qualified enough to do it. Often, he does this on instinct, taking a more careless approach than the usual overthinking he goes through and putting himself in peril in order to protect someone. Izuku putting others' lives above his own can go to the extreme, to the point where he has little to no self-preservation. Katsuki speculates that the bullying Izuku received for being Quirkless made him internalize that his life has less worth. Izuku will routinely break his arms for the sake of others, even if it's not completely necessary, such as demanding Shoto to unlock his full potential by using his fire side. This can make Izuku somewhat short-sighted, as he continued to break his arms, despite warnings he could permanently paralyze them and cut his hero career short. Eventually, Izuku listened, adapting his battle style to not put so much strain on his body. Though when he's in a particularly tight situation, he'll pull back on old habits.

Izuku is known to help or lecture people with personal and emotional problems, regardless if it's his business or not, claiming that a hero should meddle in other people's lives. This audacious spirit, while initially viewed as perplexing or even insane by others, is also recognized by many, and has earned him the loyalty, gratitude and respect of characters that were previously antagonistic towards him such as Tenya Ida, Shoto, Hitoshi Shinso, Kota Izumi, Sir Nighteye and even the Hero Killer: Stain.

He has a strong fascination.

Izuku Midoriya is strong as hell. He can destroy the sun with 100% OFA punch, and can use 120% with the help of gearshift, surpassing the speed of sound. And use 150% with Fa jin and gearshift.

Izuku Midoriya; Deku OFA Quirks: 🔥Fa jin🎆, ⏩Gear Shift🔛, 0% to 120% Percent OFA✨, ⚠Danger sense⚡, Smokescreen🌫, Black Whip➰⛓, and Float🪁 🔥Fa Jin🎆 Passed down by the unnamed third possessor of One for All, Fa Jin allows Deku to store and release kinetic energy explosively. This unique ability amplifies Deku's attacks significantly, providing bursts of immense power or speed. Gearshift have; Low gear🔙0️⃣ 0kmph, and 🔛Second transmission🔛: First gear⏩1️⃣ 200kmph. Second gear⏭2️⃣🟧 400kmph. Third gear🔀3️⃣🟩 700kmph. Top gear⏫🔝🟪 1,200kmph. Overdrive 120,490 Kmph🔄🔟💯. Remember the emojis of gearshift:

• First gear 🔛⏩1️⃣🟦
• Second gear 🔛⏩2️⃣🟧
• Third gear 🔛⏩3️⃣🟩
• Top gear 🔛🔄🔝🟪
• Over drive 🔛🔃🔟💯🟥
• Low gear🔛🔙0️⃣⬜

And remember the emoji of the others quirk too.