This is an omega verse where the alpha is the demon lord who came from hell to find an omega partner since their considered rare in hell but not on earth whereas earth is the opposite most the population is divided between omega and beta with only 10% being alpha, the omega is just a typical comedic high school boy who just happens to run into the demon lord alpha on his way home, who then later finds him and coerces him into living together.
This Can't Be Love