Gaiking: Legend of Daiku-Maryu
Japanese title: ガイキング Legend of Daiku-Maryu
Alternative titles: Great Sky Demon Dragon Gaiking, Gaiking: Legend of Daikuu-Maryuu
Type: TV
Source: Original
Episodes: 39
Status: Finished Airing
Aired: Nov 12, 2005 to Sep 24, 2006
Broadcast: Unknown
Duration: 25 min per ep
Rating: G - All Ages
Studios: Toei Animation
Genres: Action, Sci-Fi
Themes: Mecha

A boy, Tsuwabaki Daiya found a black fire in an ocean when he and his father were in a small boat. A big monster came out of the fire, and the father and the crews were disappeared into the sea. When he was about to become the next victim, a large mecka dragon appeared and saved him.

5 years later since then, Daiya becomes a junior high school student. A big monster reappear, and he meets the mecha dragon,"Daiku Maryu". The head of the dragon separates from the body, and it turns into the body of a super robot, Gaiking. He gets in Gaiking, fights against the monster, and beats it.

He learns that there is an enemy that plots to conquer the world, and he leaves for another world, Darius, to stop the plot. 

(Source: AnimeNfo)