Far out at sea, hidden in fog, lies an island where monsters are said to have lived since ancient times, and people are forbidden even to go near it. The monsters there are actually friendly, and they are afraid of humans. When a lost human child named Kotake wanders onto the island, his arrival throws the monsters into a panic. They hand the little one over to Naki, a gruff red ogre, and his blue demon sidekick Gunjou. This comedy film follows what happens once the unlikely caretakers take charge.