In the original Japanese broadcast, Dairugger XV begins as an exploration robot designed to act as a peace‑keeping force. Earth's President of the Terran League, known as the Galaxy Alliance in the Voltron adaptation, orders the starship Rugger‑Guard on a mission beyond the galaxy. During the voyage, Rugger‑Guard is attacked by a ship of the Galbeston Empire, prompting the deployment of the super‑robot Dairugger XV to defend Earth. By fate, the team is compelled to assist the inhabitants of Galbeston in finding a new planet before their home world explodes, and to free them from a despotic emperor. The Japanese version of the series has no connection to the King of the Beasts GoLion series, unlike some Western adaptations.