In the original storyline as aired in Japan, Dairugger XV was simply an exploration robot, as well as an intended peace-keeping force. The Earth is in a time of prosperity. The president of the Terran League (the "Galaxy Alliance" in Voltron) launches a mission to explore beyond the galaxy. After commencing its mission of exploration, the starship Rugger-Guard is attacked by a ship of the Galbeston Empire. Dairugger, the super robot, is deployed in order to defend the Earth. It is somewhat by fate that they must help the people of Galbeston find a new planet before it explodes, and liberate it from its despotic Emperor. In the Japanese version, it does not have anything to do with King of the Beasts GoLion, as opposed to the U.S. version, Voltron: Defender of the Universe.
There are three assault team units: Land, Air, and Sea. There are a total of 15 parts referred to as "Rugger," which can combine together to form the super-robot Dairugger. The design of the 15 separate Rugger units came from the sport of rugby, since 15 players are required to form a rugby union. The U.S. version would rename the "Galbeston Empire" to "Drule Empire," along with editing a fair amount of violence and sexual content to keep the show safe for general audience broadcast.
(Source: Wikipedia)
“Once, people staked their youth on the seas. On the Seven Seas, the flames of romanticism, ambition, adventure, and aspiration burned and clashed. Now, young people of the year AD 2200 challenge the sea of stars. What awaits them there is a world beyond our imagination.”
"Having used teamwork to barely ward-off the enemy’s attack, the Rugger Team sets about exploring the planet. But the shadow of fear still lies in wait."
"The Galactic Survey Team has found an inhabitable planet, and the enemy persistently attacks them. Will they really be able to fully protect this planet?"
"The Rugger Guard picks-up a distress call from an electrically unstable space region and sends Keats Team to the rescue. But there, they find a Galveston trap."
"The Rugger Guard arrives at a planet where no creatures seem likely to live. But while exploring there, Walther Team discovers a strange group of plants."
"At space time 6:00, the Earth support fleet that is to rendezvous with the Rugger Guard is attacked by a Galveston fleet. Aki and team hear of it, and their anger explodes."
“It’s been eight months since they left Earth. Galveston has attacked them again and again. What’s the suspicion within the mind of the exhausted Commander Ise?”
“The Galveston Empire has caused a lot of trouble for the Rugger Guard. Earth’s government decides to send an allied fleet equipped with new weapons against them.”
“A hail of bombs falls on the fifth planet. Will the opportunity for dialogue between the Earth Federation and the Galveston Empire be destroyed in the darkness of space?”
“Within Galveston, judgment has been passed on the peace-inclined Teles. Meanwhile, the Rugger Guard refuses to follow orders from Earth headquarters.”
“Ise and Aki take command on the bridge, carrying-on the will of Captain Asimov. To that end, a joint planetary survey with Galveston is now underway. However....”
