Mangchi is a small boy who wields a magical hammer that helps him overcome every obstacle he faces. After a great catastrophe turned most of the world into a wasteland, he lives on the remote island of Candlestick. When Princess Poplar of the kingdom of Jemius is pursued by henchmen loyal to the conspirator Moonk, Mangchi, known as Hammerboy, joins her cause, ready to unleash his latent powers to protect humanity. The film premiered at the Big Apple Anime Fest on August 30, 2003, and was released nationwide in South Korea on August 6, 2004.