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.