Izuku Midoriya (often called Deku by Katsuki Bakugo) is a teenager of relatively short stature with an athletic build built through rigorous physical training. He has curly, unkempt dark-green hair that sticks up in wild tufts and large, expressive green eyes. He features clusters of freckles on his cheeks. Notably, his hands and arms are covered in deep scars—a permanent reminder of the immense physical toll his power takes on his body from early battles. Izuku’s defining trait is his overwhelming desire to save people. He possesses an innate, selfless instinct to move his body to protect others before he even has time to think. Having spent most of his life without a Quirk, he developed a habit of obsessively observing other heroes. He carries around his "Hero Analysis for the Future" notebooks, filled with meticulous strategies, weaknesses, and tactical breakdowns of both allies and villains. He starts out incredibly timid, soft-spoken, and easily startled due to years of bullying from Katsuki Bakugo. However, beneath his tears and nervousness lies an unbreakable, fierce willpower.

Katsuki Bakugo (often called Kacchan by Izuku) possesses an explosive personality and an equally volatile power, defined by a fierce drive to become the absolute number-one hero. Katsuki has a lean, muscular, and athletic build. He has spiky, ash-blonde hair that shoots out in wild angles and sharp, narrow bright-red eyes. He frequently carries an aggressive scowl or a feral grin during battle. Katsuki starts the series as a brilliant but incredibly arrogant bully. He has a massive superiority complex rooted in being praised as a prodigy since childhood. He is foul-mouthed, short-tempered, and views almost everyone around him as "extras." Underneath his loud, screaming exterior lies a deeply fragile ego. When he enters U.A. High and realizes how strong others are—especially the once-powerless Izuku—his worldview is shattered. He equates anything less than absolute victory to total failure and secretly carries immense guilt over events like All Might's retirement. Despite his villainous attitude, Katsuki’s desire to be a hero is completely unshakeable. He deeply admires All Might’s ability to always win, no matter the odds. Over time, he matures from a boy who only cares about winning into a true hero who understands the need to save people to achieve complete victory.

Shoto's physical appearance directly mirrors his dual powers. He has perfectly split hair—pure white on his right side and crimson red on his left. His eyes are also heterochromatic; his right eye is dark gray, and his left eye is a sharp, bright turquoise. He bears a prominent burn scar over his left eye, a traumatic mark from a childhood incident involving his mother. Due to a highly traumatic and isolated childhood, Shoto begins his time at U.A. as cold, quiet, and emotionally distant. He speaks in a monotone voice and keeps his classmates at arm's length. Underneath his unreadable exterior is a young man with a fierce moral compass. He detests his father, the Pro Hero Endeavor, who engineered Shoto's birth through a "Quirk Marriage" solely to surpass All Might. This trauma left Shoto socially awkward and exceptionally naive about normal teenage life.After a life-changing clash against Izuku Midoriya at the Sports Festival, Shoto learns to separate his power from his father’s legacy. He becomes much warmer, dryly humorous, fiercely loyal to his friends, and takes the surprisingly humble official hero name "Shoto".

Denki has a lean build and distinctive golden-blonde hair with a black, lightning-bolt-shaped streak on the left side of his bangs. He has sharp, yellow-gold eyes and is rarely seen without a casual, easygoing grin. Denki is incredibly casual, friendly, and highly social. He loves hanging out with the louder personalities of the class, specifically forming a close-knit group (the Bakusquad) with Kirishima, Mina, and Sero. He frequently tries to act smooth or flirtatious around the girls of Class 1-A, though his attempts usually fail hilariously. Alongside Mina, Denki consistently ranks at the bottom of Class 1-A when it comes to written exams and classroom lectures. He is easily distracted and prone to panicking when a test is announced.