Yu Nishinoya is Karasuno High School's energetic second-year libero. Standing at 159.3 cm (later 160.5 cm), he is the volleyball team's shortest member yet possesses a muscular build. His wild black hair spikes upward, adding roughly 10 cm to his height, featuring a distinctive bleached tuft over his forehead. During matches, he sports an elbow pad on his right arm and vibrant shirts printed with four-character idioms like "One-Man Army" or "Three-Point Headstand." Childhood fears of insects, dogs, birds, onions, and bicycles plagued Nishinoya. His grandfather, Mineo, trained him to confront these phobias, instilling the belief that fear wastes experiences. While overcoming most, he retains a dislike for moths and onions. He previously attended Chidoriyama Junior High, playing libero and gaining Miyagi Prefecture-wide fame after winning a prestigious award for his exceptional skills. Nishinoya selected Karasuno High primarily for its uniforms—finding the girls' attire "super cute" and the boys' black gakuran "super cool"—and its proximity to his home. A clash erupted during his first year with ace spiker Asahi Azumane after Asahi lost confidence against Date Technical High School. Nishinoya's attempts to rally Asahi escalated into an altercation that accidentally broke the vice-principal's vase, resulting in a one-week school suspension and a one-month club suspension. Off the court, Nishinoya is impulsive, boisterous, and unfiltered, often sparking chaos that draws reprimands from captain Daichi Sawamura. He harbors a significant crush on manager Kiyoko Shimizu; alongside teammate Tanaka, he frequently attempts to impress her, though these efforts are usually ignored or met with physical retaliation. He enjoys being called "senpai" by underclassmen and dislikes individuals receiving excessive attention, like Oikawa. Unexpectedly, he becomes shy around unfamiliar girls. On the court, he transforms into an intensely focused, calm leader. His defensive prowess earns him the title "Karasuno's Guardian Deity" for executing near-impossible receives, stabilizing the team. He invents creative names for his techniques, most notably the rolling receive "Rolling Thunder." He emphasizes libero is his chosen position regardless of height, valuing its capacity to energize crowds through spectacular saves. Nishinoya deeply values teamwork and mentorship, training first-years like Hinata in receiving techniques after being addressed as "senpai." His relationship with Asahi is pivotal; he refused to rejoin the team unless Asahi returned, believing the ace irreplaceable. During matches, he bolsters morale with declarations like "keep your eyes forward" because he guards their backs, solidifying his role as the defensive and emotional backbone. Nishinoya participated in the team's efforts to help Hinata and Kageyama pass make-up exams after they failed finals, as depicted in the OVA *Haikyuu!! vs. "Akaten"*. After high school, he retired from competitive volleyball to travel the world.