Joo Hyun and Seung Wan were childhood friends who promised to fulfill their dreams together. Seung Wan had to leave, and Joo Hyun became the singer, 'Irene' on her own, impatient for her friend to return. When Seung Wan comes back to Korea, Joo Hyun has changed a lot.

Red Velvet just debuted. Do you wonder what happens in their dorm? The four girls share a deep friendship with some hidden feelings in between. The roommates Seulgi and Joy plan to get the two together. Will their plan work?