Extraterrestrial beings have invaded our garden world, hell bent on wiping humanity off the face of the planet. The only hope is a specialised force of genetically-engineered female Pandoras and their male partners known as Limiters, who represent the last line of defense against a horrific alien force. Kazuya Aoi is a Limiter who enrolls in a prestigious academy that trains genetically-engineered soldiers. Having made a promise to his Pandora sister who died in battle, Kazuya must overcome his sadness and become the best he can be. His first major obstacle is a frigid second-year student known as Satellizer el Bridget,