In the 2030's, an earthquake destroyed most of Tokyo. The Genom corporation decided to speed up rebuilding by using boomers, smart robots that come in all shapes and sizes. But even though the public never hears about it, boomers have a tendency to go rogue, causing great damage in the process. Linna Yamazaki has ostensibly come to Tokyo to start a new job, but her true motivation is to get in contact with the Knight Sabers, a vigilante group committed to destroying rogue boomers. Linna believes she has what it takes to become a Knight Saber herself, but will the existing members of the group feel the same way?