In the year 2020, Earth is conquered by a malevolent alien life form. The last remnants of humankind barely escape death by hiding in the oceans and creating underwater ."Aqua-bases." One hundred years later, they are attempting to retake their world. The human survivors create a deadly strike force composed of one human and four, cybernetically enhanced, voluptuous young women: the motherly Midi, the spirited Voogie, the hard-hitting Rebecca, the innocent Merrybell, and the pensive Shiori. Specially trained and armed with the latest weaponry, they carry out guerrilla attacks against the alien invaders!