A military test accidentally sends a modern-day army back in time to feudal Japan. When their actions in the past begin to have an effect on the present, another unit is dispatched to retrieve them. But the commander of the lost unit has other plans: He wants to use his advanced technology to conquer Japan and change his country’s destiny.

Leopold Fieseler, a detective with the Zeon Public Peace Department/Zeon Public Safety Department is charged with investigating terrorist attacks against Zeon government officials led by an anti-Zabi group called Valkyrie. While researching to find out who were the culprits, Leopold gets into trouble when Valkryie supporters within the ZPPD/ZPSD “arrest” him for getting his hands into classified information to help find out who are the culprits for a planned terrorist attack against Gihren Zabi himself.