The tale is modern day...
Two sisters burn with a sense of justice and go vigilante against criminals.
(They're tough-looking girls full of vigor and spirit.
And really curvaceous, too. Look upon the curves!)
Their father worries about his little girls so he hires a tentacle summoner to discourage them.
"Do what you need to. Make them realize this whole vigilante thing is too much."
The summoner does as he is told.
But the tale goes well beyond this basic premise.