Rintaro Suna hails from Aichi Prefecture before being scouted to Inarizaki High in Hyogo Prefecture, where he plays middle blocker. He has dark brown, slightly disheveled hair with a middle part and narrow grayish-yellow eyes, often maintaining a blank expression. Post-high school, his physique becomes more muscular and his hair shortens slightly. Personality-wise, Suna is quiet and deadpan yet analytical with a dry sense of humor. He internally crafts snarky remarks about teammates like Shinsuke Kita or opponents like Kei Tsukishima but rarely voices them. Observant and quick to identify strategic weaknesses in blockers, he adapts his attacks accordingly. He tends to lose focus during significant leads, though Kita's presence often motivates him to refocus. Suna avoids involvement in the Miya twins' antics but occasionally records their arguments for amusement. He maintains a cautious respect for Kita, admitting to past attempts to find flaws in the captain's demeanor. During the Spring National Tournament, Suna participates in Inarizaki's match against Karasuno. A slow starter, he gradually intensifies, exploiting Tsukishima's blocking by rotating his torso mid-spike to widen his range and misdirect defenders. This adaptability allows him to score consistently and remain unblocked. He demonstrates sharp reflexes, stifling Shoyo Hinata's quick attacks and repeatedly blocking Ryunosuke Tanaka. He also serves strategically, catching opponents off-guard immediately after the whistle. Despite Inarizaki's loss, Suna shows no overt emotion and shakes hands with Tsukishima post-match. Suna's volleyball strengths center on spiking and blocking. His signature technique involves rotating his entire torso mid-spike, enabling him to hit sharp angles while retaining power and deceiving blockers about direction, making him one of Inarizaki's top scorers alongside Aran Ojiro. Defensively, he combines speed with analytical prowess to position blocks swiftly. Post-timeskip, he joins V.League Division 1 team EJP Raijin as a middle blocker, wearing jersey number 7, with improved physical stats of 189.5 cm and 79.7 kg. Guidebooks quantify his skills with high scores in spiking (10/10) and blocking (8/10). He later earns a spot on Japan's Men's National Team. After high school, Suna maintains connections with former teammates, attending matches like the Schweiden Adlers versus MSBY Black Jackal game with Motoya Komori. In 2022, he participates in an All-Star match on Team A, finding amusement in the rivalry between Atsumu Miya and Toru Oikawa. His favorite food is Chuupet jelly fruit sticks, and his pre- and post-graduation concerns revolve around avoiding entanglement in the Miya twins' conflicts, though he later regrets finding their social media jokes amusing.