The wording makes me feel like this was done in cooperation with the outside world's governments. Kinda reminds me Blood C- where japan let monsters eat a small portion of their population.
and we get to keep all of their Shirikodamas*, so it's a pretty good deal.
*Shirikodama is a mythical ball in the anus that kappa typically feed on humans for in old legends.All the managing and manufacturing of the meat are taken care of by us Kappas.The big-wigs award us money for the cooperation,This is where the humans that were brought in from the outside by the Youkai Sage are kept......or should I say, "stored".