Gantz is a pretty graphic manga in respect to sex and violence. I personally like all the blood splattering and random body parts flying every which way. Without it, I'm not sure Gantz would have the same effect on me as it does. While reading other manga of varying taste, I notice the lack of gore and macabre detail that Gantz seems to have no problem supplying.
I'm not so sure about the sex though. Gantz has got a few hentai qualities that other non-hentai mangas don't seem to touch. The feeling of having to look over your shoulder at the door (that is, if you still live with people that will freak out at the content,) whenever semi-sex scenes appear isn't really what I want to be doing since I wasn't set out to read a hentai-sort to begin with.
So this is my question. Would Gantz have the same effect if there wasn't as much sex in it? Maybe none at all? I think it might.
All the sex in the story has no vital relation to the plot. It's all superficial cuz-im-h0rny sex. None of the scenes are unifying a relationship making me think it's grown stronger, nor do they provide a necessary link in my understanding.
Then again neither does any of the sex in mangas. But would eliminating the sex, in your opinion, make a difference?