Minori is a member of MMJ!. She is a Miyamasuzaka Girls' Academy graduate, often had bad luck as a child. At home, she saw Haruka from ASRUN, who inspired her to become a long-time fan. After 50 failed auditions and 9 years, she became a full-fledged idol alongside Haruka and two others. She is optimistic, hard-working, kind, and clumsy. Appearance: Light-grey eyes, shoulder-length light brown hair. Pastel yellow button-up under pink knitted sweater and a pleated, light brown plaid skirt with belt, black socks and white sneakers.

Haruka is a member and producer of MMJ!. She is a Miyamasuzaka Girls' Academy graduate. Formerly the most popular member of ASRUN, she co-founded MMJ with Minori, Airi, and Shizuku after a falling-out led her to Miya Girls'. She is charismatic, strict, dedicated, composed, bold, and loves penguins. Appearance: Light-blue eyes, short blue hair. Orange shirt under white button-up left open with long sleeves, partially tucked into loose gray pants with a bow, and a loose silver choker.

Airi is a member of MMJ!. She is a Miyamasuzaka Girls' Academy graduate and, being a former QT member, a popular idol. She refused to stop idoling for a TV personality career, resigning from QT. After insulting Minori's idol dream, she regretted it and trained her. Airi is strong-minded, strict, reliable, protective, hates bullies, and might be a tomboy. Appearance: Cerise eyes, messy coral pink hair below shoulder with two small pigtails. Wears a grayish-blue turtleneck under a pastel yellow suspender skirt with a front zipper, and a gold bracelet on her right wrist. Hair ties are longer.

Shizuku is a member of MMJ!. She is a Miyamasuzaka Girls' Academy graduate. Unknowingly, she became the former leader and "Grand Prix winner" of 3rd gen Cheerful＊Days. She became an idol, rivaling Airi, with a "perfect idol" image. Despite initial skepticism from Cheerful＊Days members, she agreed to train Minori. Tensions led to her departure from Cheerful＊Days, and she joined MMJ!. She is kind, mature, calm, poised, bad with tech, and a bit air-headed. Appearance: Light blue eyes, long eyelashes, long light blue hair. Small mole near her right lip corner. Wears a translucent, silver lace shirt with flowers under a green strap-sleeve dress with a belt, and a light brown watch on her left wrist.