Katsuki Bakugo, nicknamed "Kacchan" by neighborhood children while growing up alongside Izuku Midoriya, displayed natural talents from a young age. Advanced reading skills, athletic prowess, and abilities like expert stone-skipping earned him peer admiration, fueling a developing superiority complex. Manifesting his Quirk "Explosion" – generating detonations from nitroglycerin-like sweat in his palms – intensified his arrogance. He frequently bullied the Quirkless Izuku, demeaning him with the nickname "Deku" as inferior. Unacknowledged resentment festered towards Izuku's inherent selflessness, which Bakugo perceived as an unmatched form of superiority. A pivotal childhood incident saw Bakugo interpret Izuku's offer of help after a fall into a stream as condescension, further straining their relationship. Openly declaring his intent to attend U.A. High School and surpass Japan's top hero All Might during middle school, Bakugo reacted with hostility upon learning Izuku also applied. He destroyed Izuku's hero analysis notebook and threatened him to withdraw. Months later, captured by the Sludge Villain, Bakugo rejected Izuku's intervention to save him, insisting he needed no help. Rescued by All Might, Bakugo later confronted Izuku, refusing to apologize. At U.A. High, Bakugo's competitive, abrasive personality and dismissal of classmates as "extras" caused friction. Excelling academically and practically, he ranked among Class 1-A's top students. Early incidents like the Quirk Apprehension Test and Battle Trial against Izuku highlighted tactical intelligence alongside volatile temper. He struggled to accept Izuku's sudden Quirk display, believing it a years-long deception. During the U.A. Sports Festival, Bakugo demonstrated respect for opponents like Ochaco Uraraka by fighting seriously, though his aggressive style drew criticism. Over time, he began cooperating, notably devising a collaborative strategy using Quirks to entertain children during the Provisional Hero License Exam. A turning point arrived when the League of Villains kidnapped Bakugo, targeting him for perceived villainous traits. Rejecting their recruitment offer, he was rescued by All Might, who retired after defeating All For One using his remaining power. Consumed by guilt over All Might's retirement, Bakugo failed the Provisional Hero License Exam. He later confronted Izuku to uncover the truth about One For All, resulting in a battle Bakugo won. All Might revealed the Quirk's history to both, making Bakugo one of the few privy to this secret. This event marked the start of a more respectful rivalry, with Bakugo assisting Izuku's training. In the Paranormal Liberation War, Bakugo intervened to save Izuku from Tomura Shigaraki, taking a fatal blow. Edgeshot sacrificed himself to repair Bakugo's ruptured heart, reviving him. Bakugo later played a critical role in the final battle against Shigaraki and All For One, using his Quirk to eliminate Kurogiri and enable Izuku's decisive attack. Post-battle, severe injuries included a paralyzed right arm and facial scars, though rehabilitation restored mobility. During the "Dark Deku" arc, Bakugo tracked down Izuku and delivered a heartfelt apology, admitting his past bullying stemmed from jealousy of Izuku's innate heroism and unresolved inferiority. Eight years post-Final War, Bakugo graduated from U.A. and became the top-ranked Pro Hero "Dynamight." Initially a sidekick for Best Jeanist, he rose to the No. 5 position. His appearance matured to a taller, more muscular build with braided hair resembling lit fuses. His hero costume retained its core design but incorporated streamlined grenade bracers. He funded a support suit allowing Izuku to continue hero work despite losing One For All. Physically, Bakugo possesses spiky ash-blond hair, sharp red eyes, and a lean, muscular build. His evolving hero costume featured grenade-shaped gauntlets, a black sleeveless top with an orange "X," and a metallic neck brace. Post-Final War, he wore a modified costume with a full black sleeve supporting his injured right arm, bearing scars including one stretching from clavicle to elbow and a stitched mark on his right cheek. Bakugo's personality combines aggression, competitiveness, and blunt honesty. Valuing victory above all, he initially dismissed teamwork but gradually learned its importance. His development included acknowledging others' strengths, seen in his mentorship of Eijiro Kirishima and tactical leadership during joint training. Though abrasive, he exhibits surprising talents in cooking and drumming. His core belief – that heroes must win relentlessly – remains, but his actions increasingly reflect a commitment to saving others, aligning with his childhood admiration for All Might.