Yoon Ian's Backstory: A unique case of transitioning from an actor to an idol. Four years after debuting as an actor, he still wasn't getting roles, so he re-entered the agency 'Baekilmong' as an idol trainee. After five years of training, he debuted with Arteon.

Song Juheon's Backstory: His parents wanted him to pursue a legal career like a prosecutor or lawyer, but Juheon wanted to enter the entertainment industry. After frequent conflicts over his future, he ran away from home in his third year of middle school. While wandering aimlessly, he met Byeolhwi, who was in a similar situation, and stayed at Byeolhwi's house while doing online auditions. However, unlike Byeolhwi who passed on the first try, Juheon failed, and the two were forced to part ways. Three years later, they reunited at Baekilmong and debuted with Arteon four years after that.

Baek Yunhwi's Backstory: Raised under a father who is the CEO of a major corporation, he followed an elite path from a young age. However, in his second year of middle school, tired of the repetitive and boring routine, he attempted a rebellion behind his father's back: joining a band. He dreamed of becoming an idol while active as a band vocalist during middle school. In his first year of high school, he convinced his father to let him participate in an idol survival program, where he debuted with a strong 2nd place finish. However, the program was embroiled in a vote manipulation controversy from the start, and while they pushed through with activities, the team eventually disbanded within a year as the members were hit with consecutive scandals. Afterward, he graduated and worked at his father's company, but a Baekilmong scout heard some recordings he had uploaded as a hobby and cast him. After three years of training, he successfully debuted with Arteon.

Jo Byeolhwi's Backstory: Lost his parents early and grew up in an orphanage. While looking for work, he met Juheon. He couldn't ignore Juheon, who seemed to be in a similar situation as he was leaving the orphanage, so he brought him to his house to live together. Later, he passed an audition first and they were separated, but when the company kept excluding him from debut lineups for five years while debuting others, he finally left. While wandering, he remembered Juheon and auditioned for Baekilmong repeatedly until he was accepted. He finally joined and debuted in Arteon alongside Juheon.

Shin Yejun's Backstory: Grew up happily in a wealthy family. Even when Yejun's career path changed from a doctor to an idol in his first year of high school, his parents supported him. Yejun dropped out of high school to focus on audition practice and successfully entered Baekilmong at age 19. After three years of training, he debuted with Arteon.