Well, it might be a story where the devil has to battle her own dark side and societal expectations to be with her loved one. There could be lots of drama and tension.
The plot could center around the devil's internal struggle to embrace love while dealing with the consequences of her demonic identity. Maybe it leads to an epic battle between good and evil for their love to prevail.
It could involve a forbidden romance where a devil falls in love against all odds. Maybe there are challenges and obstacles due to her nature.