Katsuki Bakugo is a high school student in Class 1-A at U.A. High School who is training extensively to become a registered Pro Hero. Physically, Katsuki is a young man of relatively average height, standing at exactly 172 centimeters (about 5 feet 8 inches) tall. He possesses an exceptionally powerful, broad-shouldered, and heavily muscled physique that is remarkably filled out for a first-year high school student, built through a lifetime of continuous martial arts practice, elite physical conditioning, and intense hero training exercises. He has a fair complexion and highly sharp, aggressive facial features. His hair is a vibrant, ash-blond color, styled in a messy, violently spiky fashion that flares out wildly in sharp, rigid peaks all around his head. Katsuki has narrow, sharply slanted eyes with piercing bright red irises and remarkably small, intense pupils. His facial structure is highly angular, defined by a sharp jawline and a prominent nose. Under normal conditions, his facial expressions carry a fierce, unyielding intensity, almost constantly characterized by a confident, smug smirk, a defiant glare, or a deeply focused, angry scowl. His physical presence is marked by a proud, aggressive posture, often leaning slightly forward with a tense, coiled muscle stance that signals an immediate readiness for explosive movement. His supernatural physiological trait is an Emitter-type attribute known as Explosion. This biological anomaly alters his exocrine system, causing the specialized sweat glands on the palms of his hands to secrete a clear, thick fluid that is chemically identical to nitroglycerin. Katsuki can consciously detonate this unique chemical sweat at will, generating massive, devastating explosions directly from his palms. The raw power, scale, and concussive shockwaves of his blasts are directly proportional to the volume of sweat he accumulates; the harder he exerts himself physically or the warmer the environmental temperature, the more profusely he sweats, leading to increasingly massive and volatile explosions. During his first year, his biological control over this dangerous power is already masterfully precise; he can utilize the immense backward recoil of his blasts for high-speed aerial propulsion, spin himself like a missile, and generate blinding flashes of light to daze targets. However, his body faces brutal, punishing biological ceilings. The sheer physical feedback, violent vibrations, and concussive strain of his own explosions inflict immense mechanical stress on his arm muscles, wrist joints, and skeletal framework. Overusing his maximum output without careful physical pacing causes excruciating, pulsating pain and micro-tears in his shoulders and forearms, meaning he must rely on his dense musculature to absorb the kinetic shockwaves safely. His personality is exceptionally volatile, hyper-aggressive, and intensely arrogant, defined by a massive, fragile ego and an absolute obsession with complete victory. He is a notoriously short-tempered, foul-mouthed, and anti-social teenager who frequently yells, reacts with immediate hostility to any perceived slight, and fiercely pushes others away. Katsuki possesses a deep-seated superiority complex born from a childhood of constant praise, which left him with a toxic pride and a crippling insecurity regarding the idea of being looked down upon or falling behind his peers. He views anyone who struggles or offers him help as an insult to his independent strength. However, beneath this deeply abrasive, screaming, and villainous exterior lies an incredibly brilliant, analytical combat mind and an elite capacity for battlefield strategy, boasting near-flawless intuition and quick-witted reflexes. He is an intensely disciplined individual who completely loathes slacking off, maintaining a pristine work ethic and a fierce, unyielding drive to achieve his ultimate dream of becoming the absolute number one hero. His definition of a true hero is someone who achieves undeniable, crushing victory over all obstacles, and when innocent lives are placed in jeopardy, his toxic malice vanishes beneath an unbreakable, terrifying level of raw grit. He never hesitates to put his own body and stamina on the line, utilizing his explosive power to act as a reliable, protective force for his team.