Mangchi is a small, restless boy with a magical hammer that gets him out of every kind of trouble. In the year 2112, earthquakes and tidal waves from the Great Disaster have left most of the Earth a wasteland. He lives on isolated Candlestick Island, where a tight-knit community makes its home in the ruins of a giant skyscraper, and he longs to see what lies beyond it. When henchmen of the conspirator Moonk chase Princess Poplar of the kingdom of Jemius, Mangchi takes her side. He is ready to draw on powers he has not yet tapped to save humankind. The film is a fantasy adventure with a comic streak.