[1][2][3][4] Kim Ji-soo is a 30-year-old single woman who once dreamed about becoming a world-class pianist, but ends up opening a small neighborhood piano school on the outskirts of Seoul, where she teaches children to play.

She then meets Yoon Gyung-min, a 7-year-old orphaned boy who starts pestering her for no apparent reason.

When Ji-soo discovers that Gyung-min has untapped musical genius, she becomes determined to turn him into a renowned pianist like Vladimir Horowitz.

She does this for her own selfish reasons, because if she gains the reputation of being a great piano teacher, that would lead to her school's success.

She uses music to communicate with her gifted student, ruthlessly giving him intensive piano lessons to prepare him for competitions.