Once an expert at smiling, Oowa is now enjoying life with his friends in a White Forest where they can sing and swap their memories for whatever they need. In the forest, life’s treasures just wait to be stumbled upon, and the supply of sweet memories seems inexhaustible. Or at least this is what Oowa thinks…

Oowa had been relying on those memories to keep him smiling, but one day something unimaginable happened: the memories ran out.

How can he go on without a smile?

A bittersweet journey through the White Tunnel to all the joys and pains of memory seems to be the only way for Oowa to recover. However, just as it begins, he discovers something unexpected about yesterday and tomorrow…