Ukai has dyed blond hair with brown eyes and wears a head-band. He has two piercings on his left ear. He has been told by Nekomata that he resembles his grandfather, the former Coach Ukai. In his youth, Ukai had a dark brown buzzcut, but otherwise looked the same.
Ukai's behaviour is fairly typical of a man in his 20s. He smokes and drinks and is willing to speak casually about alcohol to minors, using terms like "a first gulp of beer" to explain a volleyball tactic to Karasuno. He is quite competitive, agreeing to coach Karasuno only so he could beat Nekoma in the practice match and then staying on because of challenges he made with Nekomata. Ukai appears lazy and cranky, spending most of his time at work reading a newspaper with his legs on the counter or yelling at people for being too loud. However, he's shown to have strong coaching skills and is a hardworking individual. Ukai chose to change his work schedule to a much earlier time in the morning to make up for the time he takes off to coach Karasuno. It's also been noted that in high school and college, Ukai excelled in mentoring underclassmen and had strong analysis skills of opponents. He also said that he wasn't very good at studies to Hinata, when he asks Ukai to help him study. While at work, Ukai would yell at high school students and remark that he's out of a product without bothering to check, but he does have a kind side as he gave Tanaka, Kageyama, and Hinata free popsicles.
Keishin Ukai is Coach Ukai's grandson. He is an alumnus of Karasuno High and was a setter on the Boys' Volleyball Club eight years ago, having the number 2. He had said that even he became a regular in his 3rd year because there were other setters as regulars in his 1st and 2nd years. He continued playing volleyball in college and after graduating, he works at Sakanoshita Store, a family business he inherited from his mother's side.
Karasuno High Team Formation ArcEdit
Ukai makes several background appearances in the beginning as a cranky clerk at Sakanoshita Store. He later receives calls from Takeda, who persistently requests that he becomes the new coach for Karasuno Boys' Volleyball Team. When Takeda confronts him at the store, Ukai asks if it's just the "Ukai" name that Takeda wants and after Takeda confirms it, Ukai seems to think over it. Despite that, he rejects Takeda anyway, claiming that he doesn't want to babysit high school boys. He later reveals that he doesn't want to go back to Karasuno because of the nostalgia it invokes in him, but he's eventually convinced when Takeda reveals that he wants Ukai to coach for the upcoming practice match against Nekoma. Ukai then schedules a practice match against the Karasuno Neighbourhood Association to test the players' skills and figure out their weaknesses.
Tokyo Expedition ArcEdit
Spring High Preliminary ArcEdit
Ukai used to be a setter, but he was not a regular while in high school. This implies that he isn't an extraordinarily skilled player, a trait that he is often teased for by his grandfather.  As a coach, Ukai has very high abilities in analysis and tactics. He goes the extra distance to collect as much data on their opponents as possible in order to formulate an effective plan to counteract them.
Ikkei is Keishin's grandfather and Karasuno's former volleyball coach. Initially, Keishin claims that he isn't the same as his grandfather and couldn't coach, but he later disproves that with his sharp mentoring skills. On the surface, the two have a rough relationship with Ikkei flipping and arm wrestling Keishin whenever he finds his grandson failing to perform his responsibilities as coach. Despite that, Keishin has a lot of respect for his grandfather, going to him for advice when he needs help with his own players. Keishin is well aware of his grandfather's wish to see an official match between Karasuno and Nekoma and strongly wants to make it happen out of filial piety. Ikkei comes to watch Karasuno's matches in the Spring High preliminary rounds and is teased by spectators for watching his "dear grandson's" team, though Ikkei doesn't deny it. During the team introductions before the match against Nekoma, Ikkei is seen bragging about his grandson and feeling proud when others comment on their resemblance.
As the coach and advisor respectively, Ukai and Takeda work together to supervise the Karasuno boys' volleyball team. Initially, Ukai is annoyed by Takeda's persistent attempts to get him onto the team, but later expresses his gratitude for Takeda's efforts.The two have strong respect for each other and care deeply for the volleyball team. They would often commentate on the matches and solve problem concerning the team together. Despite Takeda's general polite and respectful attitude, it's shown that even Ukai would cower if Takeda's angry.
Ukai has great respect for his alma mater, but he is initially resistant to become the volleyball club's coach due to his own nostalgic moments on the court. After personally watching a match and being tempted by Nekomata, Ukai becomes the official coach of the boys' volleyball team just like his grandfather. Despite calling the first and second years as the "hyperactive ones and simpletons", Ukai cares a lot about his players and is always trying to do the best for his team. He would give them advice on how to improve their play and what to eat.
Ukai and Naoi were friends in high school because of their similar situations of being third years but not starting members due to being outshone by their underclassmen. Thus, they dubbed themselves the "Benchwarmers Club". However, it's implied that they haven't seen each other since then. When they meet again in the Nekoma practice match, they tease each other about their appearances and reconnect.
- "Victory goes to the team that connects." (To Karasuno, Volume 4 Chapter 27)
- "'This is the final ball!' Think that at all times, and go after it! If you don't, then in the match, you'll regret the one ball you chose to ignore during practice!" (To Karasuno, Volume 5 Chapter 35)
- "...if you only pay attention to what's 'above', you'll get tripped up from below." (To Karasuno, Volume 5 Chapter 35)
- "It's only natural for everyone to feel nervous or hyped at the opening of the first match. So it's a matter of who breaks out of it faster!" (To Karasuno, Volume 5 Chapter 39)
- "Whoa! Whoa! What's with the grim faces? Loosen up, loosen up! You guys are still doing good, okay?" (To Ryūnosuke Tanaka, Volume 7 Chapter 59)
- "I have no complaints about the morale of our team. Seijoh is vastly better in terms of experience and technique. There's no denying that if they get ahead again, it'll be extremely tough, but if we hold onto everything we've got, the momentum will turn our way." (To Karasuno, Volume 5 Chapter 35)
- "In this tense situation, [Oikawa] still managed to find the smallest gap and pulled off a feint. His calm focus on victory is terrifying." (about Tōru Oikawa during the Inter-high tournament match with Aobajohsai, Volume 3 Chapter 24)
- "Eat...eat...a little at a time...but be sure...to grow stronger." (When Ukai takes the team out to eat after they lose against Aobajohsai High during the Inter-high tournament, Volume 3 Chapter 24)
- "Don't forget the frustration and bitterness you felt losing to Seijoh. However, you don't need to hold onto the feeling of losing. Hurry up and wipe that away!" (To Karasuno, Season 2 Episode 2)
- "Don't you dare look down! Volleyball is a sport where you're always looking up!" (To Karasuno, Season 3 Episode 8)
- "In the end, his blocking is reliant on personal skill. The problem is that his skill level is high. From what I've seen, he's very good at making some very sharp reads... and he has the reflexes for his body to keep up with his split-second reads." (To Shōyō Hinata, about Satori Tendō, Volume 18 Chapter 156)
- "Yes! We finally managed to get it to come together... our total defense!!" (About Kei Tsukishima, Tobio Kageyama, Yū Nishinoya, Asahi Azumane, Volume 18 Chapter 159)
- Favorite Food: Konnyaku dumplings
- Current Concern: He's not even 30 yet but his parents are already telling him to "Hurry up and get married."
- He owns a yellow car.
- Furudate gave him his name because of his nature: "Training crows and connecting hearts, exactly as it says.”
- His voice actor(seiyuu), Kazunari Tanaka, passed away due to a hemorrhage in the brain stem on October 10th, 2016; as for who will sub as him, the production said they will make changes since it's sudden. Above quote is his final lines of Episode 8 of Season 3.
- He shares his birthday with Alisa Haiba.
- His star sign is Aries.
- He sang "Aobajou koi uta" (青葉城恋唄) in Episode 9 of Season 1.
- In Haikyuu's first popularity poll, Ukai placed 17th with 1,535 votes. In the second, he dropped to 24th with 2,084 votes.
- Keishin (繋心) - Connecting Heart
- Ukai (烏養) - Crow Nurture