Izuku Midoriya entered a superhuman society without a Quirk, enduring extensive childhood bullying. Katsuki Bakugo mockingly labeled him "Deku" to highlight perceived uselessness. Despite this adversity, Izuku sustained a deep admiration for heroes, particularly All Might, meticulously documenting hero analyses in notebooks. A pivotal moment occurred when he impulsively rushed to save Bakugo from a villain, an act of inherent selflessness that impressed All Might. This led All Might to select Izuku as his successor for the transferable Quirk "One For All," bestowed after ten months of rigorous physical training. Izuku then enrolled at U.A. High School to hone his abilities. His initial struggles with One For All caused severe self-inflicted injuries from uncontrolled power. To mitigate this, he adopted "Shoot Style," focusing on kicks enhanced by Iron Soles integrated into his red boots. Over time, One For All manifested six additional Quirks from past users: Blackwhip for capture and mobility, Float for aerial movement, Danger Sense for threat detection, Smokescreen for evasion, Fa Jin for kinetic energy storage, and Gearshift for velocity manipulation. Mastering these required extensive training and adaptation, with Gearshift's recoil demanding extreme caution. His hero costume evolved through multiple iterations, starting as a green jumpsuit designed by his mother. Later versions incorporated support gear like Air Force Gloves for ranged attacks and Mid-Gauntlets for power regulation, culminating in the armored "Costume Zeta" and post-war "Costume Eta." Izuku combines analytical intelligence with strategic combat planning and an unwavering commitment to saving others, often at personal risk. His empathy extends to understanding villains' motivations, prompting him to offer redemption to figures like Lady Nagant and Tomura Shigaraki. During the Paranormal Liberation War, he isolated himself from U.A. to protect classmates from Shigaraki and All For One, adopting a colder, more detached demeanor. His classmates intervened, physically returning him to U.A. and reaffirming their solidarity, which restored his resolve. Key relationships include his mentorship with All Might, who instilled the ethos of heroic self-sacrifice; a fraught rivalry with Bakugo that evolved into mutual respect after Bakugo acknowledged past faults; and bonds with classmates like Ochaco Uraraka, who inspired him to reclaim "Deku" as a symbol of perseverance ("you can do it"). In the Final War against Shigaraki and All For One, Izuku pushed One For All to its limits, temporarily losing his arms to decay before Eri's Rewind ability restored them. The battle culminated in transferring all of One For All's Quirks to Shigaraki, rendering Izuku Quirkless again but enabling Shigaraki's defeat. Post-war, he acquired facial and arm scars, recovered at U.A., and later became a history teacher there. Technological advancements eventually allowed him to resume hero work using a nano-tech suit, achieving the rank of No. 4 Pro Hero. His ideology emphasizes that heroism transcends Quirks, rooted in the choice to aid others—a conviction solidified through saving Eri from Overhaul and confronting societal flaws exposed by villains like Stain.