I'm not sure specifically as I haven't read it. But generally, it might be about a relationship that involves someone falling in love with a 'devil' figure, perhaps exploring themes of forbidden love, moral challenges, and the consequences of such an unorthodox relationship.
Since I haven't read the novel, it's hard to say for sure. However, we can expect there to be a protagonist who is the one experiencing this unusual love. And then, of course, there would be the 'devil' character. There might also be other supporting characters like friends or family members of the protagonist who react to this strange relationship.
Typically, such a manga showcases the breakdown of harmony in cohabitation. This could be due to differences in personalities, lifestyles, or external factors. The story might focus on how the characters try to overcome these issues or if they end up parting ways.
It was uncertain whether the fairy tale was an original because there was not enough information to determine whether it came from a specific work or author. Comics are usually created by cartoonists based on their own creativity and inspiration. They can be based on existing stories, novels, movies, or other works, or they can be completely new storylines. Therefore, to determine whether a comic was original or not, one needed to look at the source and background of the comic to determine whether it was based on a particular work or author.