This is a really deep and complex story, one of the main characters has multiple personalities and this is the main focus on this manga. I love the way each personality was build, they are so charismatic that you like them even if they didn't appeared that much, the author of this manga was really careful when writting this, and the result its a wonderful, beautiful and even a little bit sad story, but the ending is just what's supposed to be. I love it.
Adam no Rokkotsu