Well, and this is just my humble opinion, the only meaningfull interaction with a woman Setsuna had was Marina, the only woman that he ever bothers to think about is only Marina, the only woman he returnts to in the end of the story is Marina. I thing it is pretty obvious what the author was intending to show us with that.
Now we have the manga with an ending that gives just a better closure.
Here is also the raw for the first and second chapter.