In the year 2050, an alien race, invade and successfully conquer the Earth. Years later the inhabitants of Mars Colony send out a desperate Liberation Force to try and reclaim their lost home world. Stig Bernard, finds himself on Earth, gathering a handful of resistance fighters and attempting to beat them.

Misonoo Nanako, a professor's daughter, looks forward to her first day at the prestigious Seiran Academy, a girls' school that caters to the rich, or in her case, those with high test scores. She soon finds that the school is polarized by three popular and talented individuals, known as the Magnificent Three. Though Nanako doesn't intend to make waves at this school, when she is tabbed to be a member of the Sorority, the brutal politics that run beneath the surface of the school's sophisticated veneer soon turn Nanako's world into one where she is unsure of her friends, her enemies, and her very identity... The only way she can vent her emotions is through her correspondence letters to a man she calls her "Dear Brother".

Many of Earth's survivors have been successfully evacuated to the Mars Base, leaving Sandy Neuman and the other remaining military forces to continue their fight against the machines. Thirty secret missile silos are the Earth forces' best bet to take down the MME citadel in Australia, but their comrades on Mars are hesitant to offer their support. Against all odds, Sandy and the gang must endure the bloodshed and try desperately to turn the tides of war - but the MME won't go down so easily...