Kim rowoon is kim inseong’s step brother, rowoon always tried to make kim inseong acept him as his dongsaeng, but inseong always keep in his mind that he don’t want to believe at other people easily, so he pretend that he hate rowoon, when the trurh that he already accept rowoon as his brother, at least in his heart. Rowoon just need to know that. And inseong need to say that before it’s too late.