Characters who first appear in The IDOLM@STER.KR.
Played by: Sung Hoon
Known to be the producer of Red Queen, he was forced out of the limelight after Suah died from her injuries sustained in a car accident and went into hiding for a year.
- The Atoner: After he decides to take up on Min-chul's offer to work for 825, Shin helps the RGP group to be a successful idol group in South Korea.
- Beard of Sorrow: Shin-hyuk grows one following Suah's death, and shaves it after he's been given his Producer role for 825.
- Big Brother Mentor: He's strict, but fair with the RGP members. For instances, he helps Suji get out of depression after he finds out that she misses Suah and is not joining in any more marathons and works in part-time jobs whenever possible.
- Catchphrase: "Competition is good for growth."
- Cloudcuckoolander's Minder: He acts in this role unfortunately to Min-chul whenever he has something extravagant in mind, but he usually allows him to do it as long as it helps RGP.
- Expy: He's the expy of the various Producer characters in the other Idolmaster games/shows.
- Hero with Bad Publicity: RQ fans hated him for indirectly contributing to Suah's death. This bothered him so much that he went to hiding and spend the days fishing, growing a bit of a beard in the process.
- Mr. Exposition: He explains what the 825 idols needs to do during their training, a role he shares with Yeseul.
- My Greatest Failure: He considers the death of Suah as his responsibility.
- Only Sane Man: To whatever antics Min-chul has in mind, and god help him if Yeseul has the same ideas.
- Tough Love: He goes hard on the girls to make sure that they're ready to debut, especially when he's had some tragic experience with an idol who had the stress consume her.
Played by: Chulmin Park
An unknown businessman who purchased Pure Entertainment and renamed it as 825 Entertainment.
- Benevolent Boss: An essentric, but benign old man.
- Cloudcuckoolander: Dude loves his cat. Dude loves his cat so much that he chose rooms based on where the cat nudged on the paper.
- Establishing Character Moment: In the first episode, he meets Yeeun and some of the other Pure Entertainment trainees in a public bus when one of them nearly sat on Mari, his pet cat. Later on, Yeseul tells them that he was able to purchase the company and rename it as 825 Entertainment.
- Running Gag: Every time Min-chul wants Shin-hyuk's praises, the latter just leaves him alone and bolts from the area as quickly as possible. This part is where some of the show's comedy comes in.
Played by: Yeseul Kang
The manager of the 825 idols.
- Expy: Lacking a "secretary" character unlike the rest of the franchise, 825 has Yeseul to fulfill the role instead.
- Ms. Exposition: She explains the situation to the 825 idols, sharing the role with Shin-hyuk.
- Number Two: Yeseul plays this role whenever she's with Min-chul doing business outside of the office.
Played by: Seulki Bae
The dance and vocal coach for Real Girls Project.
- Cliffhanger: Introduced during one as a mysterious woman joining 825 Entertainment.
Real Girls Project
Played by: Suji Lee
A young marathon runner who lost her popstar twin sister in a suspicious accident. She is recruited to 825 Entertainment to discover the truth about her sister's death and to continue her dream. Suji is the de facto leader of the Rookie Team.
- Angsty Surviving Twin: Suah's death left her with some pretty big emotional scars, which neither she nor the idol community at large will let her forget.
- Arc Symbol: Suji has a motif of balloons throughout the story, representing her father and childhood.
- Don't Think, Feel: The way Suji performs operates on this. Despite her apparent lack of dancing skill, she just needs to get into the music to perform well.
- Expy: She is one of both Chihaya and Mami, sharing the former's emotional trauma at the loss of a sibling in a car accident, and possessing the desire of the latter to escape her twin sister's shadow and establish her own identity.
- Good Luck Charm: The Producer's shoelace serves as one to her, since he replaced her broken one with his and encouraged her at that time.
- The Hero: The main protagonist of the show through her perspective.
- My Sibling Will Live Through Me: Since Suah died without truly achieving her dream of being an idol, Suji decides to complete that dream for her.
- Nice Girl: She treats everyone nicely, even if it means putting up with their antics/problems.
- Plucky Girl
- Replacement Goldfish: It's hard not to think that part of the reason why Suji was picked was because of her physical similarities to Suah. The guest judges in Episode 3 even accuse the Producer of doing this when she was brought up.
- Rookie Red Ranger: Considered the center of the Real Girls Project due to her resemblance to her sister. She hasn't even been an idol for very long though.
Played by: Yeeun Lee
A cheerful yet shy waitress who was hired to 825 Entertainment. She has a talent for writing lyrics and is known to have a long history with fellow member Jeewon. She is a member of the Rookie Team.
- Heterosexual Life-Partners: Was this with Jeewon and became this with Suji.
- Imagine Spot: Yeeun is the only member to receive these, as they show her struggles with adjusting to her roommates in the 825 dorm.
- The Pollyanna: Despite enduring quite a few hardships in the past and fighting to stay in Real Girls Project, Yeeun is overall an optimistic idol.
- Shrinking Violet
- Trauma Button: As Suji tries to fix Yeeun's hairclip, Yeeun gets a flashback to her time with Jiwon just before her betrayal and snaps at her.
- We Used to Be Friends: With Jeewon. They were the best of friends and even helped each other audition, but Jeewon took her spot for an audition and fell out of friendship with her.
Played by: Mint (Kunpat Phonpawiworakun)
A rich young woman who came to 825 Entertainment from Thailand. She is well known for her dancing skills and is a member of the Rookie Team.
- Dark-Skinned Blond: In most official artwork for the series, Mint is portrayed with a deep tan with her blonde hair. In-series proper, she does have a bit of a darker complexion than the other girls.
- History Repeats: Mint chose to leave her agency for the darker and edgier Y Entertainment, but ultimately returned to her original agency. Miki Hoshii pulled a similar stunt during THE iDOLM@STER SP.
- Innocently Insensitive: She's very direct with Jiseul, talking about her part time jobs straight to her face and feeling proud that they could work their schedules around it. In general, she comes off as ignorant of less wealthy people, which especially pisses Jiseul off.
- Nice Girl: She treats everyone nicely like Suji, although she can sometime say/do something that makes someone very angry at her.
- Rich in Dollars, Poor in Sense: Mint is the daughter of a powerful and rich businessman, giving her access to anything she wants, when she wants it. The first thing she does when she gets her shared space is give her roomie a luxury bed. However, she seems like she doesn't really know what it's like to be poor or struggling, which is where she and Jiseul butt heads.
- Token Minority: One of the two-non Korean members in 825 Entertainment, hailing from Thailand.
Played by: Haseo Kwon
A street performer hired by 825 Entertainment to be Real Girls Project's rapper. She is a member of the Rookie Team, although she seems to be hiding her idol life from her family...
- As Himself: Taken to the extreme with Haseo, as many of her casual wear costumes featured in the drama were from Haseo Kwon's personal clothing.
- Battle Rapping: With various K-pop idols, such as Euna Kim, appearing as guest competitors.
- Fantasy-Forbidding Father: Haseo's struggle with her grandfather goes essentially put her under house arrest and he refuses to let her have contact with her idol friends.
- Neat Freak: Much to Sori's surprise, Haseo is incredibly tidy and goes to great lengths to keep her room clean.
- Street Performer: Started out this way in the drama and is featured several times busking with other idols.
- Why Couldn't You Be Different?: Haseo's grandfather and brother often attempt to force a traditional lifestyle on her, but she is determined to follow her dreams to be a singer.
Played by: Jiseul Cha
A cool and hardworking young woman who joined 825 Entertainment in order to make money for her family. She works several jobs and is supporting her younger siblings mostly on her own. She is a member of the Rookie Team.
- Berserk Button: Mint accidentally pushes one for Jiseul for telling her to skip "a few shifts" since she keeps missing practice. Jiseul is furious, since those jobs she works are the only thing she can do to keep supporting her siblings, and its not like she wanted to be in that position either.
- The Dutiful Son: As the oldest sibling in a group of three, Jiseul works part time jobs in her off-time to raise money for her family. It eats up a lot of her idol time though, and becomes the source of conflict in the early episodes.
- Expy: She is one to Yayoi, also being an eldest sibling who has to work hard and scrounge as much money as she can to support her younger siblings. She is, however, considerably more stadoffish and aloof than Yayoi.
- In-Series Nickname: Cha.
- Jerkass: Standoffish and aloof, compared to chatty, peppy Mint.
- Only in It for the Money: Jiseul joins 825 mostly just to ensure her siblings can afford an education and a place to sleep.
- Promoted to Parent: She's forced to provide for her younger brother and sister before the start of the show due to circumstances.
- Triple Shifter: Works at a few different jobs all over the city in order to get money for her siblings, on top of being in Real Girls Project. She doesn't get a lot of sleep and has it eat into her practice time as a result.
Played by: Youngjoo Hur (adult), Hanbi Ryu (child)
A tough and resilient young woman who originally was a Pure Entertainment trainee. She became the leader of the Debut Team and refuses to give up despite the mounting pressure.
- Always Second Best: Nothing seems to go right for Youngjoo. Every team she was a part of debuted before she did, and when time came to find a new leader for Killer Queen, she was passed up. Now that Suji has started to find her footing, Youngjoo feels that all-too-familiar jealous feeling towards her as well. It's later revealed that someone she knows from the management side at Y Entertainment prior to joining B-Side sidelined her secretly with Nakyung.
- Expy: Youngjoo's intentions seem very similar to Shiho Kitazawa from the Million Live! series.
- Hard Work Hardly Works: Of all the girls in the Real Girls Project, she's the one that worked the hardest to get where she is today, but she's never been able to debut.
- In-Series Nickname: The President calls her "Smarty" from the first episode onwards because she looked like the smartest of the Debut Team.
- Kids Are Cruel: Youngjoo is on the receiving end of bullying at school while still a child trainee.
- Real-Life Relative: With Joungjoo.
Played by: Sori Kim
The oldest member of Real Girls Project and a trainee from Pure Entertainment. She often plays the mediator between the tough Youngjoo and the younger members of the Debut Team.
- Christmas Cake: Sori's friends (excluding Nayoung) see her this way and seem to shame her when Sori admits to being an idol.
- Expy: Sori's age, attitude, and love for anime get a few comparisons to Nana Abe of Cinderella Girls.
- Heroic Self-Deprecation: Sori slips into this after failing to lead the Debut Team and learning that her father hid tha fact that he had been diagnosed with cancer.
- Performance Anxiety: While Sori has several good qualities as a leader, she falters when given the opportunity to do so for the Debut Team. This is not helped by Youngjoo's authoritarian style leadership or Yukika and Jane's easygoing natures.
- Team Mom: She's always advising the other girls to stop fighting, offering to settle disputes, and making everyone sit together for meals.
Played by: Yukika Teramoto
A funny and sarcastic member of the Debut Team who started out as a Pure Entertainment Trainee. She is Japanese, making her Real Girls Project's second overseas member alongside Mint.
- Big Eater: Every other appearance she's asking when she can eat, and her metabolism allows her to plow through food as much as she can. She even demonstrates she can eat her own fist if she wanted to.
- The Face: She acts as the main spokesperson for the Japanese side of .KR, for obvious reasons.
- Raven Hair, Ivory Skin
- Token Minority: One of the two-non Korean members in 825 Entertainment, hailing from Japan.
Played by: Jane Chun
The youngest member of Real Girls Project, and formerly a trainee under Pure Entertainment. She is a fun loving girl, but often finds herself at odds with Youngjoo while on the Debut Team.
- Attack! Attack! Attack!: Uses this method to capture Yukika's stalker after taking pictures of them in the dark.
- Best Friend: Jane and Yukika are rarely shown apart and often joke around together.
- Brutal Honesty: Jane is not afraid to say what's on her mind, which has its ups and downs.
- I Just Want to Be Normal: Jane seems to struggle the most with balancing her normal life and idol life during the missions. A lot of the reason she runs away (besides her infighting with Youngjoo) relates to her not being able to be with friends or go to a normal school.
- Tired of Running: After being tired of Youngjoo's incessant rule over the Debut Team's styles, Jane confronts the problem head on. Unfortunately, the situation spirals and sends her on the run.
Played by: Jeewon Lee
A girl who had betrayed Yeeun in order to become an idol, but was ultimately asked to join Real Girls Project after her career struggled. She replaces Taeri after the trainee drops out of the project.
- Cruel to Be Kind: Jeewon's motivation for joining Real Girls Project was to be aggressive towards Yeeun in order to get her out of her depression and help her continue to follow her dreams.
- Never the Obvious Suspect: Despite a multitude of evidence, it is ultimately found that Jeewon did not actually hide the Rookie Team's costumes.
- The Rival: Became this to Yeeun, and even went so far as declaring that only one of them should be allowed to join R.G.P.
- Sixth Ranger: Only joins the team after the initial 10 were recruited.
- We Used to Be Friends: With Yeeun.
Played by: Taeri Jung
A cute and slightly clueless young woman who became a member of Pure Entertainment with the help of Youngjoo, Sori, Yukika, and Jane. She joined the Debut Team, but struggled heavily during the audition process. She eventually drops out of Real Girls Project, but finds her own career as an actor alongside her brother.
- Ascended Extra: Despite not technically being a member of R.G.P., Taeri has appeared at .KR promotions and occasionally performs with the group.
- Extreme Doormat: Taeri becomes this way after enduring a lot of verbal abuse from her fellow trainees.
- Performance Anxiety: When Taeri is given the lead role in a mission, she is relentlessly harassed by Youngjoo. This combined with her eating disorder ultimately cause her to pass out and drop out of the Real Girls Project auditions.
- Real-Life Relative: To Taewoo Jung, who made a guest appearance as her older brother.
- Weight Woe: Due to stress the of hard lessons and the competitive atmosphere of auditions, Taeri develops an eating disorder. When Youngjoo calls her out on gaining weight, she spirals out of control.
Played by: Kaeun Lee
A former Pure Entertainment trainee who left her old teammates and joined Red Queen. She calls Youngjoo occasionally in attempts to start trouble between the two groups.
- Alpha Bitch: She's a Type 2 variant, who's mean to her ex-Pure Entertainment when she was given the offer to join RQ. Nakyung pretends to cry when in public so that the public thinks that she's the victim.
Played by: Sojin Jo
The de facto leader of Red Queen after Suah passed away.
Played by: Sunyoung Kim
A rapper in Red Queen, easily recognizable with her short, dark hair. She is never seen without the other members of Red Queen.
Played by: Hyeri Han
A singer in Red Queen who has a very distinctive voice. She is never seen without the other members of Red Queen.
Played by: Suji Lee
An outgoing and popular idol who passed away under mysterious circumstances. She is the twin of Suji and one of the members of Red Queen.
- Plot-Triggering Death: The series starts with Suah's car accident, making the need to fill in another spot for Red Queen.
- Posthumous Character: She still has a huge hold over the main cast, even after death. She also gets plenty of flashbacks to show how she was in life.
- Small Role, Big Impact: Her death forced Shin-hyuk to isolate himself from the public and Suji to join 825 in order to carry out her legacy as an idol.
Played by: Joungjoo Hur
The younger and sickly sister of Youngjoo. She aspires to be a singer-songwriter, but lost her voice due to an illness.
- Ascended Extra: Despite not technically being a member of R.G.P., Joungjoo has appeared at .KR promotions and occasionally performs with the group. She was even featured in the series' soundtrack, twice!
- Image Song: Joungjoo wrote and sang her own song, "Because of You", which was promoted on the show.
- Real-Life Relative: With Youngjoo.
- Soap Opera Disease: Joungjoo lost her voice much like Chihaya Kisaragi did in THE iDOLM@STER.
Played by: Coco Lee
An MC and popular internet celebrity who often manages some of the Real Girls Project events.
- Ascended Extra: Despite not technically being a member of R.G.P., Coco has appeared at .KR promotions and occasionally performs with the group as an MC or with Sori as a cross-promotion for Cocosori.
- Image Song: Coco's debut single, "Wishy Washy", was promoted during the airing of the show.
- Promoted Fanboy: Coco and Sori both performed iM@S songs and created analysis videos based on the series prior to auditioning for .KR.
Played by: Nayoung Jin
A friend of Sori and supporter of Real Girls Project.
- Advertised Extra: Nayoung was put into several promotional pictures to advertise for the drama, but she has very little plot significance.
- Muggle Best Friend: Nayoung is this to Sori within the drama, and is one of the few characters who isn't aspiring to be in the entertainment industry.
- Those Two Actors: Nayoung and Yeseul both were members of the K-Pop group Wings prior to auditioning for .KR.
- Mr. Exposition: She's the one who broke the news to Suji about why Shin-hyuk was last seen with Suah in the eighth episode.