Duke Fleed is a survivor of the Fleed Planet who is escaped to the Earth, onboard a mysterious spaceship, where is raised by Dr. Umon as his adoptive son, and known as Daisuke Umon. Years after his arrival, he's faced with the threat of King Vega and his army, who want to conquer the Earth. With his friends Koji and Hikaru (and later his younger sister Maria Grace), Duke decides to fight back using his best weapon - the almighty Grendizer.

The Chojin Crown, the tournament which Mantaro (Kid Muscle) reluctantly participates in. After going along with the obstacles (most of which were created to try and eliminate him), he qualified. (Source: Wikipedia)

Fantasies and miracles never interested Ayu Tateishi, a popular second-year student at her middle school. She was content with preserving her image of being cool, calm, and collected—all to catch the eye of her crush, Tetsushi Kaji. Ayu's carefree youthful days are interrupted by the appearance of Nina Sakura, a new transfer student who turns out to be a witch. As the only person who knows about Nina's ability to cast spells using a mini-computer, Ayu is forced to help Nina with her mission to find the five Holy Stones, qualifying her to marry the prince of the Magic Kingdom. Unfortunately, Nina's ineptitude with magic and her habit of meddling in Ayu's personal life cause nothing but trouble for the two of them as Ayu toils to maintain her good reputation and Nina struggles to hide her secret from the discerning eye of Hiroki Tsujiai, Tetsushi's best friend and an avid fan of manga. And when Nina's search for the five Holy Stones brings allies and challengers from the Magic Kingdom, Ayu is dragged into a world she never even dreamed was possible.

Ultra B (UB), is a small child from outer space who wears red sunglasses and has a star-shaped mole on his left cheek. It all began when UB's spaceship made an emergency landing in the forest. Lost and alone, UB was found by a young school boy named Michio. He was kind enough to take UB home for shelter, but only to learn that he was no ordinary child... but with supernatural powers! Thankful UB tries to use his special power to help Michio in trouble, but doesn’t mean that it always work out well. Especially, when UB sees a scary black cat, he loses control, and… (Source: TV Asahi)