Keishin Ukai, grandson of Karasuno High's legendary former coach Ikkei Ukai, attended the school eight years prior as a setter wearing jersey number 2. He spent most of his high school career benched, only stepping into official matches after the starting setter's injury. Ukai continued playing volleyball in college and later joined a Neighborhood Association team. Professionally, he runs the family store, Sakanoshita Market, inherited from his mother's side. Initially refusing Karasuno's coaching requests from faculty advisor Ittetsu Takeda, Ukai cited a desire to avoid nostalgia and disinterest in "babysitting" students. His reluctance ended upon learning of a practice match against rival Nekoma High. A personal rivalry with Nekoma's former setter-turned-coach motivated his temporary acceptance. Ukai projects a gruff, laid-back exterior, often seen smoking, drinking, or appearing irritable at work. Yet he possesses sharp analytical skills developed through mentoring underclassmen during his playing days. He adjusts his store schedule for coaching duties and displays unexpected kindness, like giving players free energy bars. He openly acknowledges his past academic struggles. As coach, Ukai identifies team weaknesses like receives and arranges assessment matches against his Neighborhood Association team. He prioritizes player growth over immediate wins, evident when he let Hinata struggle against blockers to foster self-reliance during the Nekoma match. He adapts strategies mid-game, such as instructing Kageyama to deliver softer tosses. His decisions balance sentiment and pragmatism, notably choosing Kageyama over third-year Sugawara after recalling his own frustration as a benched player. His coaching style echoes his grandfather's, using similar nicknames and philosophies like "Man has no wings, so he must find other ways to fly." He consults Ikkei for player development advice, such as Hinata's training. Post-timeskip, Ukai continues coaching Karasuno while managing Sakanoshita Market, his hair now naturally dark instead of dyed blond. The Nekoma rivalry becomes a driving force; after losing the practice match, Ukai vows long-term coaching to defeat them nationally. This commitment carries through the Interhigh Tournament, where he prepares the team by analyzing opponents like Date Tech and Shiratorizawa, emphasizing resilience over reputations. His partnership with Takeda balances the team's needs: Takeda handles administration while Ukai provides technical guidance. Their dynamic evolves into mutual respect and friendship.