Actually the title says everything.
Way too long story description
An angel and a demon are send down to earth for checking on the humans behavior, trying to keep the balance between good and bad. None of them can return to their home, since those kind of demon and angel, which can control humans are only born once a century. Normally [ANGEL] and [DEMON] weren’t the next who should take care of this job but the two who should currently do that died. Sadly both of them can’t stand each other because [DEMON] is annoyed by [ANGEL]'s permanent optimism and seeing the good in everything while she’s annoyed by [DEMON]'s unmotivated and pessimistic way of life. That makes it hard to focus on their job and is also a danger to the human world. But they don’t have a choice since for this century they’re the only ones of their kind. If they don’t give up their anger and don’t do their job right their family will see them as a total failure and they have no right to be seen as part of their family or of Heaven’s/Hell’s residents ever again. It would be easier if they could separate but they have to work together in the same place at the same time. If they separate their powers will get out of control and human could find out what they really are, so that is not an option unless they want to show the secret world of Heaven and Hell to the humans and risk to turn all three world into a total chaos.
And: The main characters do not have and will not have a romantic relationship!
I really appreciate it if someone could help me!