A 2nd-year at Inarizaki High School and a member of the volleyball club. Position: Setter. He calls his twin brother, Osamu, "Samu," and is called "Tsumu" in return. While he has a habit of spitting venom with a smile, he is a volleyball idiot who purely loves the sport and is basically childish. According to Osamu, "his mental age drops by five years during a match." Both brothers have a tendency to act impulsively. He is treated like an idol, with girls making fans just to cheer for him. Speaks with a regional drawl (Kansai). Very handsome. Gets caught up in lucky pervert accidents.

A 2nd-year at Inarizaki High School and a member of the volleyball club. He is Atsumu's twin and calls him "Tsumu." They have different hair parts and colors (Atsumu is blonde, Osamu is silver). He is calmer than Atsumu, but since they share the same DNA, he can be just as violent in his attacks. He and Atsumu have been fighting since they were kids, which has become a famous spectacle at their school. According to Ojiro, "the luckiest thing about Atsumu is Osamu." Judging by his favorite foods, current worries, comparing volleyball to a meal, and his future dreams, he is definitely a big eater. Speaks with a regional drawl (Kansai). Very handsome. Gets caught up in lucky pervert accidents.

A 2nd-year at Inarizaki High School and a member of the volleyball club. Jersey number: 10. He is in Class 2-1, the same as Osamu and next door to Atsumu. He has a distinctive look with unique side-swept hair, a center part, and cool, narrow eyes. His hair is black/dark brown, and his eyes are a light green. He has a bit of a slouch. Originally from Aichi Prefecture, he was scouted to join Inarizaki. Because of this, he is the only one in the group who speaks standard Japanese, though his intonation has become slightly influenced by the local dialect. He has a bit of a lazy personality and is a slow starter. He is generally a downer with a calm atmosphere. His hobby is taking photos and videos with his smartphone. Gets caught up in lucky pervert accidents.

A 3rd-year at Inarizaki High School. Captain of the volleyball club. He has silver hair with black tips. Static electricity is his weakness. He was raised by his grandmother. Height: 175cm. Speaks with a regional drawl (Kansai). Very handsome. He is calm, collected, and values steady, daily effort. Gets caught up in lucky pervert accidents.