I loved my friend's friend

Monstar – Season 1

Sun-woo can't help but feel saddened that his first love is interested in someone else. A producer from JDC scouts the school for a band battle and sets up a rematch between Color Bars and All For One, but Sul-chan has his group's comeback to worry about. Adam's past is revealed, and Sul-chan confides in Se-yi about how his friendship with Sun-woo became tarnished. Se-yi makes her decision between Sul-chan and Sun-woo.