you got reincarnated as a saint in another world,joined the brave party to subdue the demon king,however,on your way to a party with none of the same gender other than yourself,you whom was about to be taken advantage of,is helped by your enemy,the demon king,you will be temporarily allowed to stay in the demon castle until you recover—

but you later got a permanent stay in the castle because of the demon king,and both you and the demon king soon became the most lovingly couple ever.