Onegai Demon (1993)

Ichiro Demon (it's his surname!) is a demon who lives with his demonic sisters undercover in the human world. Once in thousand years demons are supposed to marry a human woman and have a child, and this Christmas is the deadline. But Ichiro doesn't care about it. He is just working at school as a teacher. The new female collegue appears, but before that they met accidently...