Ogi is a sensitive boy with synesthesia; he sees sparkles of color when hearing noises or looking at people. Tachibana is a strong-willed girl whose world is gradually turning grey, afflicted with a severe form of color blindness that's slowly robbing her of her ability to see in full color. When Tachibana saves Ogi from what she thinks is a suicide attempt, two worlds - one bereft of color and one overflowing with it - collide.