Eagle-eyed fans may have noticed a familiar face in the crowd during the semi-finals of Upretty Rapstar Season 2. When host SanE announced the families of the semi-finalists, ASTRO member and To Be Continued star Moon Bin was there to cheer on his younger sister, Sua!

Sua is the youngest contestant on this season of Unpretty Rapstar. The 16-year-old rapper is a currently a YG trainee hoping to make her debut. Sua's full name is Moon Sua, and her older brother is 17-year-old Moon Bin of Fantagio's new idol-actor group ASTRO, which just made their debut through the web series To Be Continued earlier this year.

Since the two are just over a year and a half apart in age, they have always been very close. There are even adorable videos of them playing together as children! 

You totally see the little sister/bg brother dynamic in this one. So funny!

Could these two possibly be any cuter?

And, last but not least, one of them practicing their dance moves. Sua only turned 16 in September, but she has been a YG trainee for over 5 years!

Are you rooting for Sua in her battle against Yubin in the semi-finals? The episode featuring their battle will be available on DramaFever next week! In the meantime, see if you can spot Moon Bin n the first half of the semi-finals below: