Haneul was just another girl in school that no one noticed. She was mysterious and no one dared to go near her. On the other hand, Suga was an outgoing popular kingka that was part of Bangtan Boys, also known as BTS, together with his 6 other friends. There was nothing in common between Haneul and Suga, except for one thing — their passion for music. What will happen if Haneul finds a guitar at the rooftop?