Ryūnosuke Tanaka is a second-year student at Karasuno High School and a wing spiker on the volleyball team. He sports a shaved head and sharp blue-grey eyes, lending him a delinquent-like appearance that belies his true nature. He stands 177.2 cm (later 178.2 cm) tall, weighs 68.8 kg, and maintains a lean, athletic build. Previously sporting dyed blond hair early in high school, he shaved his head seeking a fresh start and greater maturity following impulsive behavior. Tanaka displays a loud, hotheaded personality, easily provoked into confrontations. He struggles academically and adopts a slacker attitude, often arriving late to practice. Yet he possesses deep loyalty and protectiveness, especially towards underclassmen Shōyō Hinata and Tobio Kageyama. He visibly thrives when addressed as "senpai" and reacts fiercely to anyone belittling his peers, like during Tsukishima's taunts. His enthusiasm erupts in over-the-top celebrations, including spinning his shirt overhead after scoring. He exhibits strong mental fortitude, rarely buckling under pressure from opponents or repeated blocks. Periodically, approximately every six months, he grapples with self-doubt about his mediocrity but consciously dismisses these thoughts. Tanaka harbors a pronounced interest in girls, particularly team manager Kiyoko Shimizu, proposing to her upon their first meeting. He and libero Yū Nishinoya act as self-appointed protectors of Kiyoko. His volleyball ties began early. In fourth grade, he defended classmate Kanoka Amanai from bullies, encouraged her to embrace her height, introduced her to volleyball, and consistently supported her despite her struggles. They lost contact after he transferred. At Karasuno, initial impulsiveness nearly led him to retaliate against unfair treatment of the club, but observing his seniors' maturity inspired him to redirect his passion positively. Tanaka evolves from a volatile underclassman to a reliable upperclassman. He mentors Hinata and Kageyama, organizing early morning practices and involving his sister Saeko for transportation to camps. His skills as a wing spiker steadily grow: he masters powerful cross and straight spikes, develops a pressure-inducing jump serve by Nationals, and learns the "inner-cross" spike technique from Bokuto Kōtarō. His spike reach is 324 cm and his block reach 312 cm. His gameplay emphasizes strategic vision, enabling clever attacks and consistent support during critical moments. Post-graduation, Tanaka becomes a personal trainer and sports instructor. He marries Kiyoko Shimizu.