Giant robo - the day the earth burned manga

Giant Robo: The Day the Earth Burned summary:

In the mid-1990's, Yasuhiro Imagawa adapted Mitsuteru Yokoyama's original manga, Giant Robo, into a 7-part OVA series entitled Giant Robo: The Animation - The Day the Earth Stood Still. Imagawa's adaption strayed far from Yokoyama's Giant Robo, featuring a mostly original storyline which included characters and elements pulled from several other Yokoyama projects, such as Tetsujin 28 and Babel II. Giant Robo: The Day the Earth Burned is another story set in the universe created in Giant Robo: The Animation, in which young Daisaku Kusama commands Giant Robo, the mightiest robot of our world, in the battle against the underground terrorist organization known as Big Fire.