In the last decade or so, those damn humans have been lengthening their lifespans.

Deaths and births have instead been on the decline.

Here in the underworld, people have been saving every bit of their souls to keep the lights on. As a result, we demons need to be extra careful when we make contracts with humans now.

Our only wish is to cling onto their bodies and suck their blood dry, drop by drop! Just like a parasite!