The story revolves around Duke Fleed who is a survivor of the Vega Star, raised by Dr. Umon as his adoptive son, and known as Daisuke Umon on Earth. 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 kid sister Maria Grace), Duke decides to fight back using his best weapon, the almighty Grendizer.
as Duke Fleed / Daisuke Umon (voice)
as Koji Kabuto (voice)
as Genzo Umon / Great King Vega (voice)
as Hikaru Makiba (voice)
as Danbei Makiba / General Gandal / Nuke / Whiter (voice)
as Goro Makiba / Lady Gandal (voice)
as Grace Maria Fleed / Commander Marine (voice)
as Science Minister Zuril (voice)
as Blaki / Bunta Arano (voice)
as Akira Hayashi (voice)
as Hara Arano (voice)
as Boss (voice)
as Mucha (voice)
as Captain Gorman (voice)
as Commander Mineo (voice)
as Ainzu (voice)
as Commander Kirika (voice)
as Kane (voice)
as Zuril Junior (voice)
as Princess Rubina (voice)
as Vénusia (voice)
as Actarus / Prince d'Euphor (voice)
as Alcor (voice)
as Professeur Procyon (voice)
as Minos (voice)
as Rigel (voice)
as Mizar (voice)
as Véga, le Grand Stratéguerre (voice)
as Hydargos (voice)
