Yoi, a 17 year old high school drop out, joins International Millitary Organization to be come a "Platinumhugen" pilot. Without ever piloting the giant robot even once, he showed extradinary skills in his first practice. For some reason he seem to have "memories" of piloting "Platinumhugen". Unknown to him, the person in charge of his team''''s training is actually his older sister which he has no knowlege about. There seems to be a lot more going behind each of his teammates: Lena, his childhood friend, and the IMO Commandent''''s daughter; Olfe, a german pilot of exceptional skill; and a mysterious girl who have super human abilities that came out of no where. Everyone seem to have their own agenda and past as the plot unfolds.