Bubblegum Crisis: Grand Mal was a 4-issue prequel by Adam Warren. This is the collection. Out of print.

From the publisher:

Mega-Tokyo, 2031. The Great Kanto earthquake six years earlier has left scars the city won't soon forget. Even as its glorious Genom tower rises higher with repairs, in its shadow creeps a new wave of crime, a sign that beneath the growing prosperity and recovery is an undercurrent of discontent . . . a world on the brink of exploding. And if the Armored Defense Police can't prevent the bubble from bursting, then the four-woman vigilante unit known as Knight Sabers will suit up for action!