Isekai AV 01

The story is about Kyoutarou Koto, a JAV director who suddenly got transported to a fantasy world and captured by the demon lord's forces. The demon lord, who is actually a cute girl, tells him he will die if he has no value to the demon kingdom but if he proves his worth, he will become her husband. Conveniently, the demon kingdom has a device that can record and project videos so he tells her he will make adult videos so the population of their rival kingdom will gradually be reduced, which he explained is currently happening to his world (Japan's population is falling as a result of AV because people just masturbate and don't have sex anymore).

If you're looking for a funny and interesting hentai manga with lots of erotic scenes and good art, then this book is for you.