My Guardian Angel from Hell [ J.SY & S.YQ ]

Heaven opens its pearly white gates once a millennium, with the purpose of allowing only ONE demon from Hell to surface and receive a special assignment in exchange for one wish that can be granted if they are to succeed.

Now, Yuqi of the fifth circle must prove herself worthy to complete a rather odd assignment. In exchange for her wish-which is to seek salvation in Heaven-she must become a guardian angel for a human.