Heavenly Jewel Change - Chapter 26

Masaru Ryunosuke is an outcast—a scholarship student in a school of elites, struggling to keep his head down in a world that looks down on him. But when a chance encounter with a vampire attack leaves him at death’s door, he wakes up to a new reality—he's no longer human.Now a ghoul, the lowest rank of undead, Masaru finds himself thrown into a world of ancient bloodlines, deadly supernatural creatures, and secret organizations hunting beings like him. His only guide? Akane Mikazuki, the cold and ruthless noble vampire who saved him, but only for her own mysterious reasons.Armed with the Cape of Dracula, an artifact of legendary power, and an unnatural potential that defies vampire logic, Masaru refuses to accept his fate as a weakling. If the world wants to treat him like a mere undead—then he’ll rise above them all and prove them wrong.As battles erupt between vampires, werewolves, assassins, and monstrous beings, Masaru must claw his way up the supernatural hierarchy before he’s devoured by forces beyond his comprehension. Because in this world, the weak exist only to be devoured.But what happens… when an undead refuses to stay at the bottom?

Polygamy is abolished.

We don’t have to force ourselves to live together anymore…

Yo, Hi! I’m Frank, I made a deal with a demon to pay me some money for receiving a guest for a few days every week.
I had no idea about what I have done.
On May 1st, Conan ‘the God of Death’ came to my house. I was forced to let him in and we get involved in a criminal case.
On May 8th, Bruce Wayne ‘Batman’ came to me. I was forced to follow him to fight crime.
On May 16th, Hannibal Lecter, The Silence of the Lambs, came to my home. I can only say that I really can’t stand my guests.

- Description from Novelupdates

220 years ago, in the legendary Dragon Demon War, Hero Azell ended the war by killing the evil Dragon Demon race’s King Atein. He was able to save the population, but as a consequence, he was cursed. While he was dying, the high magician suggested a gamble that might save his life.