I've been looking for series that relate with proportionally unbalanced "male to female ratio". For instance, take a gander at this Hagio Moto manga called Marginal. The characters in the futuristic world had to cope the lack of females and opts to genetically create new humans instead. There's also this oneshot in OBRIGADO! about the paradoxical view about the loss of men or women in two separate locations.

I'm not sure if there is a thread/category for this, but it would be much helpful to post related stuff for this search. (If it does, feel free to lock the thread)

Just to be clear, it must have some kind of futuristic vibe and events triggering the circumstance.

No ecchi or hentai please. Please look at my Unfinished List if you would.

Whether we fall by ambition, blood, or lust,
Like diamonds, we are cut with our own dust.

Oooku is the BEST manga of this kind that you'll find. Anywhere.

Operation Liberate Men might sort of suit, but it's less "skewed" in terms of numbers and more in terms of equality...

Edit: Oh, and even though this isn't a manga but an American comic book series, try Y: The Last Man. It's a really smart and interesting take on what happens when there's only 1 guy left on Earth...

Zero (YAMAZAKI Takako) deals with this theme (the male : female population ratio is said to be 7:1); but the project was dropped by its scan group.

Rather than skewered, I think you meant "skewed"... haha ^^

Anyway, tartufo beat me to it, but I definitely second Oooku. Viz is releasing it in their Signature line, amazingly good quality books, just don't let the weird archaic English put you off at the start. It starts to flow better later and you get into it

世界のどこかに必ず
キミの居場所がある筈

@mogiks, yeah, the archaic English is a bit weird at the beginning (my guess is that the original Japanese used was formal/archaic and the translation attempts to reflect that?) but you get used to it quickly, thanks to the amazing storytelling. Oooku is DEFINITELY my manga purchase of the year; if I was a billionaire, I'd buy one copy of it for every person on Earth, lol. It should be recommended reading for every human being, it's such a universal masterpiece. 😀

I liked 'skewered'. Mmm, kebabs. <3

Sorry for the typo, guys. Yes, I meant "skewed". I must be hungry when typing this. 😛

@ tartufo & mogiks:
I already have Ooku in my list and I actually bought all the released 4 volumes so far.

@ calstine:
A shame about the project status.

Thanks for the suggestion. Keep 'em coming.

Whether we fall by ambition, blood, or lust,
Like diamonds, we are cut with our own dust.

Love DNA XX