I'm looking for a manhwa..

There's a siblings, a big sister and a little boy.. One day, there's a boy almost the same age with the big sister becomes their brother.. I don't remember how.. they became singers together~ And then, one day, the boy had to leave to america.. the siblings family had a bankrupt after they live in luxury for years.. the boy became one of famous boy there.. One day, because of her brother sickness, the big sister have no choice but to enter a singing competition.. Or maybe it was something else.. The boy, for the 1st time he went to this competition just to see her after looking at the participant's name list.. But, he act as if he came for the old pal among other participants.. And so I stopped reading after that..

Please help me search for this!!
What I can help is it's definitely not one-shot, no Yaoi,Yuri, Shounen-Ai, Shoujo-Ai, Mature, Adults, Josei and so one such as Mecha..

PLease Help!

Just a guess.
Feel So Good
Most likely not, but worth a guess. It revolves around a brother and sister in the showbiz, but the thing that the boy is older and the sister is younger. I think that's the main difference with the discription, but I'm giving it a shot anyways.

I think you are talking about Show Princess.