Tobio Kageyama is a volleyball prodigy first seen as a junior high student at Kitagawa Daiichi. His exceptional setting skills earned him the "King of the Court" nickname, stemming not from admiration but from his authoritarian playing style. He demanded perfection from teammates without regard for their capabilities or input, breeding resentment and isolation. His passion for volleyball began in childhood playing with his grandfather Kazuyo and older sister Miwa; he was drawn to the setter position for its frequent ball contact. During his third year at Kitagawa Daiichi, teammates' frustration peaked when they refused to hit his tosses in a critical match, resulting in his benching and the team's loss. This rejection, compounded by failing to enter his preferred high school Shiratorizawa and his grandfather's death, deeply affected him. He enrolled at Karasuno High, unexpectedly encountering former rival Shoyo Hinata. Their initial antagonism caused conflict, leading to temporary banishment from the team until they demonstrated cooperation. At Karasuno, Kageyama focused on overcoming his dictatorial approach. He learned to adapt his sets to his spikers' abilities instead of forcing them to meet his standards, notably modifying his "King's Toss" into a more controllable set with backspin. His partnership with Hinata became central to Karasuno's strategy, marked by their collaborative "Freak Quick" attack relying on mutual trust—Kageyama's pinpoint accuracy and Hinata's speed and jumping ability. This growth extended off the court; he became more respectful toward upperclassmen Sugawara and Daichi and tolerated divergent viewpoints from teammates like Tsukishima. Though initially enraged by references to his "King" nickname, he gradually reconciled with its meaning. Kageyama possesses extensive technical prowess. Beyond his setting genius, he excels at powerful jump serves (later incorporating precise aim and spin variations), dump shots, and emergency spiking. His analytical mindset shows in his meticulous volleyball journal and rigorous self-discipline during training. Post-high school, he joined Japan's V.League Division 1 team Schweiden Adlers, later moving to Italy's Serie A team Ali Roma. He represented Japan at the Rio Olympics at age 19 and continued with the national team. Physically, Kageyama has sharp features, dark blue eyes, and a lean, muscular build. His default stern expression contributes to an intimidating aura. Post-timeskip, he reaches 188 cm in height and sports a middle-part hairstyle with short bangs. Personality-wise, he remains intense and socially awkward—often perceived as sullen or abrasive—yet reveals underlying childishness, sensitivity, and enthusiasm during volleyball successes. He dislikes crowds and hot weather, enjoys pork curry with egg, and harbors a persistent worry that animals dislike him.