In 2029, a massive earthquake destroyed Tokyo; in the present day, its residents are still trying to pick up the pieces. Out to assist is DC, an organization charted with conducting research and cleaning up the city with the help of giant robots. Ken is a young man who has been training to get into the DC, but fails to be accepted into their ranks. However, when a giant white robot materializes, Ken jumps into action and subsequently is accepted into DC's ranks. Joined by his friend Mizuki, entitled Lyune and other new recruits, Ken tries his best to protect the city against the white monster. But soon, Mizuki is pulled into another dimension and returns with the startling truth behind the robot - and when attempts are made on Mizuki’s life, it becomes harder and harder to tell who the real villains truly are...