Walking beneath the cherry blossoms with Tomoko — a childhood friend who has always thought of him differently than he thinks of her — the protagonist finds a girl lying unconscious under one of the trees. The shock of recognition is immediate and impossible: this is the girl he fell for in high school, the one who died in a car accident. She is here. She is breathing. What she is doing under the cherry trees with no memory of how she arrived, and what her presence means for the future he thought he understood, is the question that sets the rest of the story in motion.