Once upon a time, a courageous and powerful lad named BOOK defended the Monster-Land from the earth invaders. Since that heroic battle, many, many years have passed, but the account of his bravery has secretly been passed down from one generation to the next.
Our two happy-go lucky characters, Leo & Papillo, quite by chance, happen to hear about the legendary deeds of BOOK and set out to prove that they can be as gallant in battle against the enemi as he had once been.