help me pleaseeee

I cant remember the name of this manga for the life of me and i've read it like 3 times TT
the story was about a demon who had white hair, and he has to go to earth to kill someone (i think???) and he lands on top of a school and meets this little girl, idk what happened next but they ended up getting married and the priest tries to kill the demon?? and stuff happens uhhhh
fck i really dont make any sense rn AHAHAHA but i remember it was v wholesome and fluffy
pls help me find it i wanna reread it again it was so good :(