Ryo Yamada is a reserved, eccentric, and deadpan high schooler who serves as the bassist and composer for Kessoku Band. Despite her wealthy background, she is notoriously broke and tactless, often spending all her money on instruments, often causing her to ask for money from her friends. She often does not show a lot of outward emotion but that doesn't mean she doesn't have it. Ryo has short blue hair with two black square hair clips on the right side of her bangs and light golden chartreuse eyes, with a mole on her left cheek.

Ikuyo Kita is the cheerful, energetic, and charismatic guitarist and lead vocalist of Kessoku Band. A social butterfly, she joined the band out of admiration for bassist Ryo Yamada, later learning the guitar from Hitori. Kita is highly sociable, athletic, and loves interacting with people. She is constantly active on social media (Isosta) and maintains a bright, sunny disposition.Kita has red hair with grown-out bangs and bright Chartreuse eyes.

Hitori (Nicknamed bocchi) is an extremely introverted girl with high social anxiety, making it very difficult for her to talk to strangers. She often tries to avoid interactions, even performing her first live house show from inside a cardboard mango box. Because of her introversion, she rarely goes outside and instead spends most of her time at home, playing the guitar alone in a dark closet.She seeks praise from others, likely as a reaction to her personality.Hitori Gotoh is characterized by her long, straight pink hair with a side ahoge on the right side of her head, typically adorned with a blue and yellow cube hair clip on the right side of her head. She has large aqua-blue eyes and a fair complexion, often accompanied by a somewhat vacant or anxious expression.

Nijika is primarily a very kind, sweet, altruistic and friendly girl. She is outgoing, though not as extremely extroverted as Kita. She's naturally very accommodating and makes others feel at ease. She was exposed to band culture at an early age due to the influence of her older sister, Seika, who was once in a band and is now the manager of a live house, and is familiar with the music industry. Nijika has long blonde hair with a floating, triangular ahoge worn in a side ponytail and vermilion eyes