An ordinary girl somehow gets to another universe and becomes (wakes up as) a demon. She makes (or tries to) friends with an Angel Girl but every time she does something good for the angel something even worse happens to her. The Angel Girl tries to protect the Demon Girl by refusing her and being cold towards her. This is not a shoujo-ai (damn it).

is it disagea? 😀 oh wait... they both are demons... theres an angel tho.

It Is shoujo-ai lol.. look: Stray Little Devil