Twelve years ago, Japan was attacked by a mysterious monster; in response, 21st Century Security built a giant robot called Dai-Guard, but by the time it was ready, the creature had disappeared again.

The fighting may be over, but the paperwork is just beginning, as damage claims and lawsuits related to Dai-Guard's last mission start piling up.

With rumors flying around about a new division being created to take charge of Dai-Guard, the team decides to demonstrate that they are the best people for the job.

Faced with the prospect of having to turn Dai-Guard over to the army, Akagi becomes determined not to make a single mistake.