Mystic Story rookie boy group ARrC will be appearing as guests on the October 5 broadcast of JTBC's 'Knowing Brothers'.

On this episode, the members of ARrC will compete against the cast members of 'Knowing Brothers' in a quiz battle. While the ARrC members will showcase their expertise in all things Gen Z, the 'Knowing Brothers' cast members intend on displaying their knowledge of Y2K. 

Furthermore, during the episode's recording, it was revealed that ARrC members Doha and Jibeen were in fact friends and classmates of Lee Soo Geun's son, Lee Tae Joon. The two idols, who once went over to Tae Joon's house to hang out, recalled what it was like seeing Lee Soo Geun at their friend's house. "We only ever saw him on TV, but when we saw him at Tae Joon's house, he was such an adult," the ARrC members said, causing laughter.

You can watch ARrC on this week's episode of 'Knowing Brothers', airing on October 5 at 8:50 PM KST. 

SEE ALSO: Red Velvet's Yeri confirms new start with Blitzway Entertainment