Totsuko, a high-school student who attends a Christian Academy in Nagasaki, can see the hearts of people as colours. Whether they’re happy colours, sad colours, peaceful colours, or frightened colours. In order to not darken the “colours" of her friends and family, Totsuko is careful to read the room and stretches the truth to keep them all brightly coloured. Totsuko then meets a beautiful girl who radiates very striking colours and a boy who loves music in a used bookstore in the corner of town. The three come together and form a band to make the music of their adolescence (Edited from Crunchyroll's description).