Pororo and his friends were having fun when a little red dragon named Arthur appears above them. Arthur, who claims to be the king of dragons, commands Pororo and his friends to search for his Dragon Heart. Just then, the jewel Arthur has brought emits a magical force that turns Crong into a giant dragon, while a mysterious light from the sky abducts Pororo and his friends to the Dragon Castle. It turns out that Ged the Wizard has taken over Arthur’s throne, in an attempt to capture Crong for the Dragon Heart. Would Crong and his friends be able to return home safely?