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.

"Girls" follows four beautiful women and depicts the troubles found in their love lives and work place. Yukiko Takigawa (Karina) works at a big advertising firm and has a good looking boyfriend. Seiko Takeda is married and has no children. She works at a large real estate company. Yoko Kosaka is a single woman working at a historic stationary company. Takako Hirai is a single mother who works for a car manufacturer.

A group of friends from high school days reunite for once more time before one of them dies from cancer.