Sunmi and Zico as well as MONSTA X's Shownu and Jooheon teased their guest spots on 'Knowing Brothers'.

In the behind-the-scenes clip above, the four idols tease their appearance on the JTBC variety show with self-interviews. Sunmi says, "It's my second time here, and I hope I appear more than before. Last time, I came with Jang Yoon Joo, and I have a fear of variety shows. I didn't really appear that much." 

Jooheon, who's appearing for the first time, expressed, "I'll make sure to liven up the atmosphere of this classroom." When Zico asked Shownu if he prepared anything for the show, Shownu said, "I prepared a couple dance with Jooheon." Sunmi and Zico also revealed they prepared a collaboration performance.

In other news, Sunmi recently made a comeback with "pporappippam", while Zico returned with "Summer Hate" featuring Rain. This episode of 'Knowing Brothers' aired on July 11 at 9PM KST.