Kon'ya no Okazu wa Range de Marine

Renji is a uni student, living a peaceful life. One day, he meets two people, one is a princess of the devil world who ran away from the devil world because she doesn't want to marry him and another one is her fiance. Unfortunately, Renji gets involved in their quarrel... and unknowingly, Renji pretends to be her fiance in the human world. No one notices this will be the dawn of full of H life....