The eldest son and twin of Joo Dantae and Shim Suryeon (Na Aegyo). He is taciturn and blunt, but he takes great care of Shim Suryeon and his younger twin sister, Joo Seokkyung. He graduated from Cheong-ah Arts Middle School. (Yoo Jenny and Bae Rona attended a different regular school.) He isn't the type to speak up first, but he will step forward if his people are in danger. He is abused by Joo Dantae. (However, no one knows about the abuse except for Seokkyung, Suryeon, and Dantae. Since he is hit on the arms and body rather than the face or hands, it isn't easily noticed.) He is the smartest among the Hera Kids and possesses the most strength and fighting ability. He lives on the 100th floor of Hera Palace. He is in the piano department. He gets along well with the students at Cheong-ah Arts High. (Except for Ha Eunbyeol.)

The youngest daughter and twin of (Joo Dantae) and Shim Suryeon. She is prideful, hates losing, and is calculating and cunning, but deep down she is very fragile and has some goodness left. She graduated from Cheong-ah Arts Middle School. (Yoo Jenny and Bae Rona attended a different regular school.) She considers Ha Eunbyeol and Bae Rona her rivals, but since Eunbyeol is currently her biggest eyesore, she pretends to be close to Rona just to get under Eunbyeol's skin. She cherishes Seokhoon and Suryeon, though she sometimes says harsh things she doesn't mean. She is abused by Joo Dantae. (However, no one knows about the abuse except for Seokkyung, Suryeon, and Dantae. Since she is hit on the arms and body rather than the face or hands, it isn't easily noticed.) However, she isn't very bright and often ends up trusting Dantae. She cheats on mock exams and midterms/finals by coordinating with the other Hera Kids and Seokhoon. She lives on the 100th floor of Hera Palace. She is in the vocal department. She gets along well with the other Hera Kids. (Except for Ha Eunbyeol.)

The son of Lee Kyujin and Go Sang-ah. He is immature, sly, mischievous, and very frivolous. He is a classic case of being weak to the strong and strong to the weak, bowing down obsequiously to those of higher status. He graduated from Cheong-ah Arts Middle School. (Yoo Jenny and Bae Rona attended a different regular school.) He is currently in a 'some' relationship with Yoo Jenny. He lives on the 55th floor of Hera Palace. He is in the vocal department. He gets along well with all the Hera Kids.

The daughter of Yoo Dongpil and Kang Mari. She is arguably the kindest among the Hera Kids, but she looks down on others just as much as the rest, and like Lee Minhyuk, she is sly and sarcastic. Before coming to Cheong-ah Arts High, she attended the same middle school as Bae Rona and has looked down on Rona since then. She is currently in a 'some' relationship with Lee Minhyuk. She lives on the 45th floor of Hera Palace. She is in the vocal department. She gets along well with all the Hera Kids.

The daughter of Ha Yooncheol and Cheon Seo-jin. She entered Cheong-ah Arts High through her mother's influence. She shows extreme anxiety when she fails to perform a task perfectly and harbors a one-sided crush on Joo Seokhoon. (However, Seokhoon's rejection is so firm that she can't even approach him properly. She isn't exactly the 'sly fox' type.) She pretends to be kind in front of others but is very calculating behind their backs; she doesn't even bother pretending with Bae Rona, whom she hates and envies intensely. She graduated from Cheong-ah Arts Middle School. (Yoo Jenny and Bae Rona attended a different regular school.) She also views Joo Seokkyung as a rival. She lives on the 85th floor of Hera Palace. She is in the vocal department. She gets along with most Hera Kids. (Except for Seokkyung; she wants to get along with Seokhoon, and while Rona isn't a Hera Kid, they are in a completely hostile relationship.)

The daughter of (Ha Yooncheol) and Oh Yoonhee. She is exceptionally talented at vocal music and had the skills to enter Cheong-ah Arts High on her own, but due to variables like Min Seol-ah and Ha Eunbyeol, she was initially waitlisted as candidate #1. She was admitted after Min Seol-ah's death. Before Cheong-ah, she attended the same middle school as Yoo Jenny, where she almost faced school violence charges because of Jenny, though the situation was resolved. (She did not actually commit any violence.) She has a crush on Joo Seokhoon and is rivals with Ha Eunbyeol. She is kind-hearted and upright; she cannot ignore injustice and will not overlook even a family member's evil deeds. (For now) she is bullied and ostracized by the Hera Kids except for Seokkyung and Seokhoon, but she never gives in and always stands her ground. She lives on the 45th floor of Hera Palace. (She originally lived in Bosong Village but moved to Hera Palace after property values skyrocketed.) She is in the vocal department.