A young boy named Shu is obsessed with becoming a Knight Master's apprentice after he hears that one has appeared in his village. Shu goes in search of him, only to find that the traveler is not a Knight Master at all, but a woman called Zola with the power to transform her shadow into a winged, purple-furred monster called Killer Bat. When the village is attacked by soldiers from the Grand Kingdom, Shu inadvertently unleashes his own Shadow, Blue Dragon.