Once every five years, a special chime echoes through the school in this town. Luna, a transfer student and an art-loving girl, laughs it off as "nonsense"—but she holds a hidden past. Without realizing it’s a reunion, she meets the protagonist, "me", again. Their bond, and the secret of her parents’ work hidden behind the chime, begin to resurface. A sound heard only once every five years ties the two together once more. Includes Japanese voice acting.