Gaiking: Legend of Daiku-Maryu

Daiya Tsuwabaki was on a boat with his father when they encountered a fire in the ocean. The flames were extinguished, but a massive monster emerged, and his father was swept away. Daiya was saved by the arrival of a giant mecha dragon.

Five years later, Daiya entered junior high school. He soon faced another monster attack and met the mecha dragon, Daiku Maryu, which transformed into a robot called Gaiking. Daiya piloted Gaiking to defeat the monster.

Daiya learned that a global threat existed and traveled to the planet Darius to thwart the enemy's plans.