Keishin Ukai

Height: 178.2 cm / Weight: 72.2 kg / Birthday: April 5 / Favorite food: Tama konnyaku / Recent concern: Being told to get married soon even though I'm not even 30 yet / Age: 26 years old

A former member and coach of the Karasuno High School boys' volleyball team.

A smoker, he usually helps out at his maternal family's store, Sakanoshita Shop, and later becomes the owner of the shop.

He is the grandson of the legendary coach Ukai who led the Karasuno High School volleyball team to prominence. Although he loves volleyball enough to form a neighborhood team, he initially disliked coaching others. However, during his high school and college days, he was skilled at mentoring juniors and analyzing opponents. Hearing of his talent, Coach Takeda repeatedly asked him to become a coach, and he finally agreed to help when he learned they would have a practice match with Nekoma High School. Initially, he agreed to coach only until the Golden Week practice match with Nekoma, but he continued after being provoked by Coach Nekomata. According to Coach Nekomata, the reason for the provocation was that "he looks like his grandfather (Ukai)”. When his own coaching skills were insufficient, he sought advice from his grandfather, the former Coach Ukai, for Hinata, and discussed the basic theory of blocking with Tsukishima, admitting, "I'm not good enough to be a model... someone better close by would be Kuroo from Nekoma," showing a sincere coaching attitude.

As a player, his position was setter. In high school, he only started in one match when a junior setter was injured, and this experience made him hesitant to bench Sugawara. However, he decided to do everything he could to help the team advance. His deep analysis of both his own and other teams often led him to give passive instructions during matches. This passive approach was overcome by the growth of the players and Sawamura's leadership by the quarterfinals of the Spring High preliminaries. Coach Washijō from Shiratorizawa Academy commented, "The way of fighting hasn't changed even in the grandson's generation!" During the fifth set of the finals at the Spring High preliminaries, when Shiratorizawa Academy took their second match point (14-15) and the team members were shaken, he encouraged them by saying, "Don't look down! Volleyball is a sport that always looks up!"

He planned to improve the team's serving level by the Spring High Tournament, designating the period during which Kageyama and Tsukishima were attending training camps as "Serve Strengthening Week." As of 2018, he is still coaching the Karasuno High School volleyball team.