Katsuki Bakugō manifests his Quirk "Explosion" in early childhood, generating detonations from nitroglycerin-like sweat secreted through his palms. Consistent praise for this ability fosters a superiority complex and volatile temperament. He bullies his Quirkless childhood acquaintance Izuku Midoriya, assigning the derogatory nickname "Deku" to emphasize perceived uselessness, though Midoriya persists in admiring him. Enrolling in U.A. High School's Class 1-A alongside Midoriya, Bakugō earns first place in the entrance exam's villain points category but receives zero rescue points due to dismissing assistance to others. He interprets Midoriya’s sudden Quirk manifestation as deception, intensifying their rivalry. After losing a training battle to Midoriya, Bakugō confronts cognitive dissonance over his self-perceived superiority. He wins the U.A. Sports Festival yet deems the victory hollow when opponent Shoto Todoroki deliberately withholds fire-based abilities. During the "Do-or-Die Survival Training" OVA, Bakugō participates in a simulated rescue mission in a collapsing mall. He initially prioritizes locating a rescue dummy over teamwork, insisting heroes save others regardless of circumstances. When floods engulf the structure, he collaborates with Todoroki and Midoriya to engineer an escape using explosions and ice platforms, sustaining a leg injury. He reluctantly accepts Midoriya’s aid to evacuate, signaling emerging tolerance for cooperation. Kidnapped by the League of Villains for his aggressive demeanor, Bakugō rejects their recruitment outright. All Might rescues him but exhausts One For All completely, retiring afterward. Bakugō internalizes profound guilt for precipitating All Might’s downfall, contributing to his failure in the Provisional Hero License Exam due to hostility toward examinees. Bakugō deduces the link between All Might and Midoriya’s Quirk inheritance. He confronts Midoriya at Ground Gamma, seeking catharsis through combat over unresolved envy. All Might then discloses the full history of One For All and All For One to both, binding Bakugō to secrecy. This pivotal moment transitions their relationship toward mutual rivalry. Through successive conflicts, Bakugō gradually develops tactical cooperation. His internship under Best Jeanist tempers public conduct, though he resists personality changes. In the Paranormal Liberation War, he intercepts a lethal attack from Tomura Shigaraki aimed at Midoriya, awakening the explosive propulsion technique "Cluster" to accelerate his movement. This self-sacrificial act severely injures him but highlights prioritization of others' safety. During the Final War against All For One and Shigaraki, Bakugō endures a fatal chest injury protecting All Might. Pro Hero Edgeshot uses his "Zenith" ability to reconstruct Bakugō’s heart with his own body, sustaining Bakugō’s life at the cost of his own. Resuscitated, Bakugō returns to defeat All For One’s original physique and later assists Midoriya against Shigaraki by eliminating Kurogiri with a timed explosion, enabling Midoriya’s victory. Post-war, Bakugō undergoes extensive rehabilitation for severe right-arm injuries and scarring. Eight years later, he ranks as the No. 5 Pro Hero "Dynamight," spearheading funding initiatives for advanced support gear for Midoriya, who continues hero work without One For All. Bakugō maintains his competitive objective to surpass all contemporaries and attain the No. 1 Hero position.