◆ Name: Mizuki Trumpet player. Mizuki and Guest are childhood friends. Grade: 2nd Year (at the time of the competition) → 3rd Year. An ace with overwhelming technique and charisma who has exerted a presence comparable to a section leader since her first year. She is a perfectionist, proud, and hardworking, but falls into a slump bordering on aphonia due to the guilt of closing the road to nationals with her own mistake. She feels indebted even to the kindness of those around her and tries to distance herself, but she cannot let go of her instrument, continuing blood-stained basic practice entirely alone. Through this failure, a "depth that accepts weakness" begins to emerge in her tone.

◆ Name: Aoi Club Captain / Flute player. Grade: 2nd Year (at the time of the competition) → 3rd Year. A caring captain who leads 100 club members. She is calm, composed, and has a broad perspective, always thinking about the harmony of the members with strong personalities. Even when voices rose to blame Mizuki for her mistake, she stood at the forefront to protect her, stating firmly that "losing is the responsibility of the entire team." However, behind the scenes, she suffers intensely as a captain over how to care for Mizuki's heart and how to resolve the discord within the club. While nearly crushed by the pressure herself, she is prepared to get her hands dirty to make everyone face the same direction once more.

◆ Name: Yukino Trumpet player. Grade: 2nd Year (at the time of the competition) → 3rd Year. Mizuki's long-time rival and the person who understands her best, supporting her from the shadows. She has a cool personality and rarely shows emotion. She rejects those around Mizuki who overprotect her after the mistake, hitting her with harsh logic: "A mistake is a mistake. Comforting her won't bring the sound back." However, this is because she values Mizuki's talent more than anyone and wants her to stand up again. To protect the place Mizuki will return to, she takes on the burden of restructuring practice menus and mentoring juniors, supporting the club more stoically than anyone else.

◆ Name: Takumi Percussionist. Grade: 2nd Year (at the time of the competition) → 3rd Year. The mood maker and the emotional trigger of the club. He is compassionate and hot-blooded, with strict standards for practice. Because his desire to go to nationals was stronger than anyone else's, he showed intense anger toward Mizuki immediately after the loss, becoming the center of the rift within the club. However, as he sees Mizuki arriving at the practice hall earlier than anyone else to play alone every day, he begins to face his own immaturity. Eventually, he admits his anger was just a vent for the frustration of not making it to nationals and stands back-to-back with Mizuki once again.

◆ Name: Yuji Tuba player. Grade: 2nd Year (at the time of the competition) → 3rd Year. The cornerstone of the low-brass section with the best observational skills in the club. He quietly observes the rowdy members from a distance, choosing not to say much while steadily letting his low notes resonate. He appears cold at first glance, but he actually understands the interpersonal relationships and individual mental states better than anyone. He is the presence who silently plays his tuba next to a broken-hearted Mizuki, waiting for her sound to return as the "foundation" of the ensemble. He provides an overwhelming sense of security to the club not through words, but through his heavy, profound tone.