Ryūnosuke Tanaka is a second-year student at Karasuno High School and a wing spiker on the boys' volleyball team. He has a shaved head with a widow's peak and sharp blue-grey eyes, giving him an intimidating appearance often mistaken for delinquency. Standing 177.2 cm tall with a lean but strong build, his physique suits his aggressive playing style. During his first year, he had short, fuzzy, light-colored hair (blond in the anime), shaved off the next day after personal reflection for a feeling of refreshment. Post-timeskip, his hair grows dark naturally, though he later dyes it light again for an event. His frequent intimidating grimaces are often chastised by team captain Daichi Sawamura for looking foolish rather than fearsome. Tanaka combines loudness, hotheadedness, and a propensity for picking fights with academic laziness and tardiness. Despite this, he demonstrates deep loyalty, protectiveness toward underclassmen, and unwavering team support. He reacts strongly to anyone belittling others, defending first-years against Tsukishima's provocations. His enthusiasm amplifies notably when underclassmen call him "senpai." On court, his fervor shows in boisterous celebrations after scoring, sometimes spinning his shirt overhead during practices. He exhibits strong mental resilience during matches, refusing to be deterred by targeted strategies, though he privately grapples with self-doubt about mediocrity approximately every six months, consciously dismissing such thoughts. Off court, he displays marked politeness around girls and harbors a significant romantic interest in team manager Kiyoko Shimizu, whose frequent indifference to his advances he finds appealing. He and libero Yū Nishinoya often jointly protect Shimizu from unwanted tournament attention. His background includes a pivotal fourth-grade friendship with Kanoka Amanai, whom he defended from bullies teasing her about height. He introduced her to volleyball and consistently encouraged her despite initial struggles. They separated when Tanaka transferred schools, later attending Ōjitsu Junior High before Karasuno. Upon joining Karasuno, he immediately fell in love with Kiyoko Shimizu and proposed on sight, though she rejected him. His early first-year behavior was volatile, especially regarding perceived disrespect toward the team, but witnessing his upperclassmen's composure spurred personal growth, leading to his symbolic decision to shave his head. Tanaka evolves from a supporting player to Karasuno's ace in his third year. Key developments include mentoring first-years Shōyō Hinata and Tobio Kageyama during their 3-on-3 match against seniors, facilitating their cooperation despite initial friction. He displayed patience when Hinata vomited on him during the Aoba Johsai practice match due to nervousness. His gameplay emphasizes power and tenacity, improving cross and straight spikes after training camps. By nationals, he masters a reliable jump serve capable of pressuring opponents. His resilience shines in critical matches, overcoming targeted serving through sheer mental fortitude, earning coach recognition for maintaining performance under pressure. Post-graduation, he becomes a personal trainer and marries Kiyoko Shimizu, who works at a sports apparel store. Tanaka's athletic abilities prioritize power (rated 5/5) and stamina (4/5), with lower initial technique (2/5) and game sense (2/5), though Daichi observes his tactical understanding is underrated. His vertical jump reach measures 324 cm for spiking and 312 cm for blocking. His signature quality is an unwavering refusal to give up on any ball, coupled with consistent performance in high-stakes situations. Ukai identifies him as Karasuno's second-strongest spiker after Asahi during his second year, highlighting his aptitude for thriving when cornered—a trait aligning with his later ace role. His relationships define key growth aspects: his dynamic with Nishinoya centers on shared exuberance and troublemaking; his mentorship of Hinata and Kageyama blends encouragement with disciplined guidance; and his persistent courtship of Shimizu culminates in marriage. Minor trivia includes his fondness for melon bread, exceptional hearing, and Pisces zodiac sign. His name, chosen by series creator Haruichi Furudate for its "cool" and "Tanaka-ish" qualities, combines "Ryūnosuke" (Assistance of a Dragon) and "Tanaka" (Rice Field Middle).