Synopsis
Duke Fleed is a refugee from the planet Fleed who fled to Earth. He was raised aboard a mysterious "spaceship" by Dr. Umon, who adopted him, taking the name Daisuke Umon. Years later, he confronts the threat of King Vega and his forces, who seek to conquer Earth. Alongside his friends Koji and Hikaru, and later his younger sister Maria Grace, Duke chooses to resist using his ultimate weapon—the mighty Grendizer.