Kotaro Bokuto captains Fukurodani Academy's volleyball team as its ace wing spiker. His appearance features distinctive round golden eyes and spiky white-grey hair with black streaks styled to resemble a horned owl. He wears knee pads extending to his thighs, differing from typical volleyball attire. Post-high school, he develops a more muscular build and shorter hair while playing as an outside hitter for the MSBY Black Jackals in Japan's V-League Division 1, later joining the Japan National Team. Bokuto bursts with playful, energetic, and childlike energy, often seeking attention through dramatic actions. He experiences significant mood swings impacting his performance, leading teammates to label him "simple-minded." During low moods, his hair visibly droops. Despite this volatility, his skills and enthusiasm motivate allies and opponents alike. He forms connections easily but can overlook others' discomfort, as seen with Tsukishima. He occasionally displays unexpected wisdom, like inspiring Tsukishima during the Shiratorizawa match or advising Yachi against over-worrying. His competitive nature includes defensiveness of younger players, exemplified when stopping Kuroo, Tsukishima, and Lev from targeting Hinata during a practice match. His volleyball journey began in early childhood, with middle school teammates struggling to match his intensity. At Fukurodani, he gained recognition for exceptional skill and volatility as a first-year. Meeting setter Keiji Akaashi in his second year proved pivotal; Akaashi’s precise tosses earned immediate praise, solidifying their partnership. Bokuto initially specialized in cross spikes but switched to straight spikes after repeated blocks, mastering them to near-invincibility. He also excels at feints, wipes, and cut shots, teaching the feint technique to Hinata during a Tokyo training camp. Though ranked among Japan’s top five aces, he narrowly missed the top three. His on-court fragility paradoxically strengthens Fukurodani’s resilience, with teammates supporting him through slumps. When focused, Kuroo notes Bokuto rivals top-three-level aces. Key relationships fuel his growth. Akaashi acts as his strategic anchor, narrating Bokuto’s thoughts and stabilizing his emotions—agreeing to withhold tosses during slumps but later reigniting his confidence. Bokuto actively seeks Akaashi’s presence, valuing their dynamic. He mentors Karasuno players: his advice about finding volleyball’s "hook" moment impacts Tsukishima’s outlook, while training sessions with Hinata foster mutual admiration. His rivalry-turned-camaraderie with Nekoma’s Kuroo includes lighthearted teasing and collaborative coaching. Character development centers on self-perception. Early on, he declared himself the "strongest" ace after overcoming slumps but later acknowledged being "coddled by his team." He evolved his goal to become an "ordinary ace," redefining the term not as mediocrity but as embodying the ideal ace—reliable and excelling without volatility. Post-timeskip, he confidently asserts this maturity to challenging teammates like MSBY’s Atsumu. His broader philosophy emerges through lines like "we are the protagonists of the world," reflecting relentless ambition beyond conventional limits. Trivia includes his September 20 birthday (Virgo), love of yakiniku, and struggles with kanji and mathematics. He owns a shirt listing "The Wisdom of the Ace" principles, which he and Hinata admire. As Fukurodani’s captain, he wears #4 instead of #1, honoring the tradition that #4 signifies the team’s ace.