该片讲述了普通女高中生日奈奈认识了来学校拍摄电影的男明星绫濑枫，两人发展出一段“灰姑娘”式的爱情的故事。

Arima Kousei won numerous piano competitions while under the strict watch of his mother. He was known as the human metronome during that time. Since the death of his mother, Kousei has been unable to hear the sound of his piano. He then meets Miyazono Kaori through childhood friend Sawabe Tsubaki. Kaori plays the violin and has a free sprit. Since meeting her, Kousei is able to face the piano again. Meanwhile, Kaori holds a secret.