Mizuki and Minori are members from different units, 25-ji, Nightcord de. and MORE MORE JUMP! respectively, and are both second-year students who attend different high schools: Mizuki attends Kamiyama High School, while Minori attends Miyamasuzaka Girls' Academy.

Touya and An are well known to have opposite personalities, with An being very expressive, outgoing, and bad at studying, while Touya is more reserved, stoic, and good at studying. Despite being very opposites, they actually have a similar situation − music is become part of their life since they were kid, mainly because of their father's influence. Both of their fathers are accomplished musicians. Touya's father is a famous classical musician, while An's father is a retired musician who hosted and performed at legendary event

When she was younger, Arisa learned the piano, and she attended the same music school with Tae and Rei, where she was part of the Pianist Course.[2] However, she ended up quitting because she didn't have any motivation to continue, and also because she had to study for middle school exams.[3] When she befriended Kasumi and heard about her plans to start a band, she picked it up again so she could be the keyboardist for Poppin'Party.

Ran is the only child of the masters of a flower arrangement school that dates back to over 100 years ago, and which her father currently owns.Ran has short black hair with her short bangs partially tucked beneath her forelocks, one of which is dyed red. She has partially sharp dark pink eyes.

Rinko is a very talented keyboardist who has played the piano ever since she was 5 years old, and prior to joining Roselia, had even won in multiple music contests. She started taking piano lessons after her mother took her to watch a concert. However, she stopped participating in contests after she failed during a big one because of stage fright

Minato Yukina is a first-year student at Yotsuba Women's University and the leader of and vocalist for Roselia. She is a powerful vocalist, sparking the admiration of the other Roselia members, as well as the other people around her. Yukina has sharp, gold eyes and long silver hair worn loose with some type of black butterfly hairclip decoration. Her long forelocks rest over her shoulders, and her bangs just reach her eyes.

Soyo has long, waist-length light brown hair and grayish-blue eyes, often supporting a gentle expression on her face. Her original band outfit consisted of a white turtleneck sweater with black cuffs, a black belt with a silver buckle, and a deep blue skirt with a long outer mesh layer. Her shoes are black with a chartreuse yellow cross on each. In her casual outfit, she wears a blue-white blouse with short, puffy sleeves and a frilly neckline, a cream-colored skirt with small flower patterns, and a thin brown necklace with a star charm on it.