The transfer student, Luna Akatsuki.

You happen to meet Luna painting on the rooftop.

You walk home from school together with Luna.

Luna seems to be hiding a secret.

You and Luna go to the summer festival together.

You realize that you seem to have forgotten something.

Luna wavers.

The two of you are swallowed by the night.

I remembered something I must never forget.

Luna rings the bell that tolls once every five years.

A bell that rings only for the two of us.