In the not so distant future of Earth, a city is miraculously reborn just sixteen years after being completely destroyed by a giant meteor. Our story begins in the prestigious Graviton High School for Girls as the teather, Miss Ayumi, introduces two new students - A-ko and her ditzy sidekick C-ko. A-ko is a lively seventeen-year-old, no different from any other...except that within her diminutive frame lies superhuman strength. The trouble begins when B-ko, the spoiled, brilliant daughter of a business tycoon, decides she wants C-ko for herself. And what B-ko wants, B-ko gets. Unless A-ko is standing in the way. B-ko becomes the irresistible force and A-ko the immuvable object as the action explodes across this unsuspecting city. B-ko goes up against the invincible A-ko with her arsenal of powered robot-suits, including the most powerful of all, Akagiyama 23. Meanwhile, a monstrous alien spaceship plies its way towards Earth