Giant Robo which appeared in Okinawa. This robot is thought to be the very first Giant Robo that was created and became the basic of all other Giant Robos. GR-1 made a contract with Daisaku Kusama so he is the only one who can operate this robot. As Daisaku gets accustomed to commanding GR-1 its ability improves. GR-1 can fly by using anti-gravity system. This is a first Giant Robo found by GRO. This robot is especially accustomed to fighting under the water. The operator of this robot is changeable. The first operator was Kansas and after his death Dublin became the new operator.