Meet Ji Haneul, a gifted musician whose fingers effortlessly dance across the strings of her guitar and the keys of her piano. Her heart carries a symphony of optimism, her smile a beacon of unwavering resilience even in the face of life's challenges. On the other side of the stage is Lee Changsub, a remarkable singer with a cold exterior, whose heart remains shackled to the memory of his former love.

As fate's strings pull them closer, a love-hate relationship unfolds between Ji Haneul and Lee Changsub. Haneul's hopeful melodies clash with Changsub's guarded persona, yet an undeniable connection begins to form. Changsub's rejection of other women echoes the deep chords of his past, while Haneul's denial of her growing affection adds to the intricate notes of their tale.

Can Changsub's frozen heart find a new rhythm, breaking free from the past's haunting tune? Will Haneul's cheerful spirit finally acknowledge the tender melody that plays for Changsub, the man she once considered unapproachable?