An airborne biochemical attack occurred, where the deadly Medusa Virus had leftover 4 billion women alone to defend themselves on earth...

...after it wiped out the entire male species worldwide.

Those women, who were pregnant with the infected males' semen of the virus, soon gave birth to a Third Specie -- the new breed of mutilated-transgender - resulting in the co-existence of the androgynous male-boys. 

Many years later, the women-ruled government had taken measures, by containing some of these 'coming of age' boys, inside abandoned prisons --- so to secretly harvest their semen -- for the future propagation of womankind.

This led to the shemale mutineers creating an insurrection, which soon spearheaded a prison breakout -- and next into, a civil war against the dominatrix government.