Resume : Pero, a sword-wielding musketeer cat, is on the run! He's guilty of the ultimate crime: rescuing mice from certain doom. In hot pursuit are three bumbling police cats, trying their best to bring Pero to justice. While evading capture, Pero stumble upon an unfortunate boy named Pierre, who is mistreated by his two greedy and selfish brothers. Pero soon convinces Pierre that he is better off leaving this deprived life behind him.

The two set off together to find their fortune, and hear of an announcement from the castle: the king is looking for a husband for his beautiful daughter, Princess Rose. With the urging of Pero, Pierre unwillingly poses as a prince to woo the princess. However, the dastardly Lucifer arrives and spoils the plan when he manages to kidnap the princess! It's up to Pero and Pierre to journey into Lucifer's castle and rescue the lovely Rose.