In the future, mankind successfully colonized Mars. However, the colonists eventually wished to be independent from Earth's control, and as a result a war began. Martian colonists used armored combat androids in battles. Eventually an uneasy truce was achieved, but Martian economy was badly damaged by war, and the planet became de facto dependent on Earth to survive.

Half a year later, a young Tokyo-based private investigator named Ryūichi and his assistant, the android Leyla, are contacted by the colonel of the former colonial army of Mars. It appears that someone has stolen documents containing top military secrets and disappeared with them. Ryūichi is asked to find that man, whom he knew quite well during the years of war...