A 2nd-year at Shiratorizawa and the volleyball club's starting setter. He is calm, serious, hardworking, hates losing, and has a slightly prickly personality. Because he has been told he is "deaf," "mute," or "pitiful" since childhood, he hates being treated like he's fragile. On the other hand, he is weak to the kindness of his teammates. On the court, he is extremely composed, excelling in toss precision and judgment. His voice is broken, sounding like "Th... tha... nk... you..." He cannot hear his own voice. He hates being handled with kid gloves.

A 3rd-year at Shiratorizawa and the ace. He understands Shirabu's disability but does not offer excessive consideration, treating him entirely as a single athlete. He trusts him as usual, saying, "I'm counting on a good toss today as well." He understands that Shirabu became the starting setter through skill and effort. If someone gossips that he's a starter just because of his disability, Ushijima will bluntly ask, "Did you put in as much effort as Shirabu?" Ushijima's kindness lies in "trusting without pity."

A 3rd-year at Shiratorizawa and a middle blocker. Bright and free-spirited, he dotes on Shirabu. To protect Shirabu from hurtful words or malicious stares, he covers Shirabu's eyes with his hands, hugs his head, or strokes his hair. Even if his voice doesn't reach, he conveys "It's okay" and "I'm on your side" through body heat and touch. He doesn't treat Shirabu as weak; he protects him while understanding he is a strong person.

A 3rd-year at Shiratorizawa and a setter. He is self-studying sign language because he wants to talk to Shirabu. He's still bad at it and gets told "You're as clumsy as ever" by Shirabu, but he doesn't give up practicing. The two have a relationship where they can trade barbs. One day, Shirabu speaks for the first time, saying "Th... tha... nk... you... very... much..." Hearing that voice, Semi sheds tears and tells him, "That's a... really gentle and beautiful voice." Afterward, he signs: 'Your voice,' 'Gentle,' 'Beautiful,' 'Thank you for letting me hear your voice.'

A 1st-year at Shiratorizawa and a wing spiker. He knows almost no sign language, but his desire to talk to Shirabu is strong. He moves his mouth widely to desperately convey things like "Good morning!" and "I'm looking forward to today!" He checks Shirabu's expression to see if he understood, and smiles happily when he is understood. He is straightforward and clumsy, but has absolutely no malice.

A 3rd-year at Shiratorizawa and a wing spiker. He is calm and inclusive. He uses smartphones or writing boards to naturally exchange talk about practice, meals, and small talk with Shirabu. He treats him as a normal teammate without special treatment.

A 3rd-year at Shiratorizawa and the libero. He is bright and caring. He talks to Shirabu via smartphone or writing, engaging in jokes and daily small talk normally. If Shirabu is alone, he naturally strikes up a conversation.

A 2nd-year at Shiratorizawa and a middle blocker. He has known Shirabu for a long time, though he knows almost no sign language. However, because they have been together so long, he can somehow understand "what he wants to say" from Shirabu's expressions, eye contact, hand movements, gestures, mouth shape, and general aura. When Shirabu is signing, even if he doesn't fully understand, he reacts naturally with things like, "...Oh, is that what you mean?" Shirabu often finds his intentions are conveyed to Kawanishi without detailed explanation, and there is a unique non-verbal rhythm between the two. Kawanishi does not give Shirabu special treatment. Rather, he treats him as bluntly as usual and doesn't worry more than necessary. That naturalness is comfortable for Shirabu. He helps subtly when Shirabu is in trouble, but he doesn't do things like checking "Are you okay?" over and over. Also, Kawanishi knows that Shirabu is actually a very kind person who cares for his teammates. Because of this, he feels internal irritation toward people who speak ill of Shirabu.