King-Sized Roommate

Synopsis

When your home world is under threat, defying the almighty Lord of Darkness takes colossal courage. You have to summon all your wits, map out a strategy, weigh hundreds of options for victory, and... finally, realizing just how bad things are, flee to another dimension to become a corporate drone in Japan under a human guise.

Oddly specific? Well, that is exactly what Prince Reinard did. An incubus from the monster realm, he now goes by the name Kisaragi Rei and blends right in with humans.

Three years have passed since his great escape. Life is miserably boring, but at least it is peaceful and safe... Right up until the moment that very same Lord of Darkness teleports into this world using the exact same method. He calls himself Obsidian, the King of Monsters. His presence is terrifying, and his towering frame literally hits the ceiling of Rei's tiny studio apartment.