the superior genes of Koo family not only produce beautiful children, but they can sing well too! iKON's Junhoe is a unique voice in kpop and he actively write songs too. his noona turned out to have awesome pipes too. btw, she's not a professional singer, she just posts covers in her YT channel sometimes. here's Yejin performing in Oh My Part, You, a new tv program in MBC. which kpop idol siblings made you feel the rest of us didn't get a fair share of good gene pool?