In Amberground, a dangerous terrain where a man-made star casts a permanent twilight, young Lag Seeing aspires to become a Letter Bee: a postman entrusted to deliver the hearts of people separated from the ones they love.

    Unfortunately, the sadistic captain of the football team already has his eye on Sena and his lightning-fast speed.

    Each round, the wolf kills a rabbit. Each round, the rabbit group tries to figure out which of the rabbits is actually the wolf in disguise and kill it. If a rabbit kills the real wolf, the rabbits win. If they're wrong, all of the rabbits will be killed. Who is the real wolf? And can they stopped it before the game is over...