In the near future, Tokyo was left flattened as a result from a great earthquake. A new city, MegaTokyo, was then recreated due in no small part from the aid of a multi-million dollar company, Genom Corp. Genom created and mass-produced biomechanical creatures called Boomers to aid in the restoration of MegaTokyo. When the Boomers began to run out of control, the ADPolice at first tried to stop them, but they proved to be far more difficult to deal with than was first imagined. Under the ever looming Boomer threat, a group of four girls from varying degrees of society banded together. Calling themselves The Knight Sabers, they were the only ones with enough firepower and resourcefullness to defend the fledgling MegaTokyo from Genom and its berserk Boomers.
Kaoru is a serious office lady who's passionate about her job. Her husband Hajime, on the other hand, is a hard-core otaku who lives a nearly shut-in lifestyle. Kaoru worries about her husband, but they get along better than you'd think.
Gene Starwind and his partner Jim Hawking run a small business on the backwater planet of Sentinel III. But all that changes the day that Hilda hires them for a bodyguard job. Now, thrust into a mystery they don't fully understand, they're on the run from the cops, the pirates, an angry alien, and a mysterious assassin. But they've got one thing going in their favor—they have the galaxy's most advanced ship, the Outlaw Star.
Yukiteru (Yuki) Amano is a loner who never really interacts with people and prefers writing a diary on his cell phone, with his only companion being an imaginary friend named Deus Ex Machina, the God of Time and Space. However, Yuki soon learns that Deus is not a figment of his imagination but real when Deus makes him a participant in a battle royale with eleven others. Within this "Diary Game", the contestants are given special diaries that can predict the future, with each diary having unique features that gives it both advantages and disadvantages.