The story centers on a boy named Mangchi. He is small, but he owns a magical hammer that helps him overcome all his problems. Mangchi lives on a small, remote island called Candlestick because everywhere else has become a wasteland due to a major catastrophe. When Princess Poplar from the kingdom of Jemius is pursued by the henchmen of the conspirator Moonk, Hammerboy sides with her, ready to unleash all his latent powers to save humankind. The movie premiered at the Big Apple Anime Fest on August 30, 2003, and went into wide release in South Korea on August 6, 2004.