Koshi Sugawara, widely known as Suga, holds the position of vice-captain for the Karasuno High volleyball team. He possesses light grey hair, hazel-brown eyes, and a distinctive mole beneath his left eye, complemented by an average height and slender build. His personality blends gentleness with keen perceptiveness, making him a stabilizing force for his teammates. Although Kageyama's arrival moved him from the starting setter position, Sugawara's dedication to volleyball remained unwavering. He continued club activities throughout his third year while most peers focused on academics, driven by a desire to avoid future regrets. Sugawara attended Nagamushi Junior High alongside Daichi and Asahi, joining Karasuno with aspirations for national tournaments. The team initially faced challenges due to poor performance and a lack of coaching. His perceptive nature surfaces when he deduces Tanaka's secret gym practices before the first-years' 3-on-3 match. Strategically adept, Sugawara devised the "bring it" and "send it to me" calls to synchronize Kageyama and Hinata’s quick attack. He also created hand signals overnight while teammates slept. His limited match experience proved an advantage, as opponents lacked data on his playing style. In the OVA *VS Failing Grades*, Sugawara appears during the academic crisis surrounding Hinata and Kageyama’s failed exams. After their unsuccessful plea to the vice principal—resulting in the accidental wig incident—he attempts to calm the ensuing argument in the club room but recoils from Daichi’s anger. He later suggests alternative participation opportunities for the first-years in future matches, though Tanaka interjects with a plan for them to join the Tokyo camp contingent on passing the makeup exam. Beyond volleyball, Sugawara attends a college prep class and favors super-spicy mapo tofu. As of 2018, following high school, he works as an elementary school teacher in Miyagi.