The story reminds me much of Ao No Exorcist. Both the male leads have a cat demon/devil companion as well. The ending wasn't that satisfactory but an ending nonetheless.
You may feel your favorite manga should be gathered together into distinct categories for your own reference and, now, you can do this with a LIST. After you've created your list or lists, you can proudly recommend them to other manga fans to showcase and share your taste in manga.
Kamisama Hajimemashita