I don't know but it seems to be inspired from a webcomic named "Devil No.4" I have found a lot of similarities.But I haven't found any review or information regarding that in other blogs or reviews. I won't be saying much about the other aspects of this drama since others have perfectly pointed out. But in that webtoon the girl was broken,had money in her hand,the story actually revolved around a Cafe.there were a few scenes where she was teleported with the Devil to sea shore since there she was under an "agreement". Eventually they fell in love,the Devil no 4 died there,he got again reincarnated and you can expect what happened after that. So I have found such similarity.