After having been sealed for 300 years, the demon lord Giri reawakens and sends off his monster minions to wreak havoc in the world. King Uruga XIII decides thus to place announcements everywhere in the kingdom in search of a legendary hero who can defeat Giri. In the king's castle will be held a competition to discover who the true hero is. Forced by his parents to go to the castle, Nike first visits the witch's house, where Kukuri joins him. Together they travel around the world defeating monsters, gaining new abilities, trying to uncover the misteries surrounding the Migu Migu tribe and meeting many friends and enemies.