According to Director, Motomu Toriyama one of the themes we'll find in Lightning Returns: Final Fantasy XIII will be Hope's growth as seen from Lightning's motherly point of view. Looks like Hope isn't the only one that has grown, though, and Lightning's body seems to have received quite the upgrade during her self-imposed crystal stasis.

During one of the Square Enix Presents livestreams at E3 with Toriyama himself and Producer Yoshinori Kitase, the host asked if they could share Lightning's three sizes. The answer was interesting to say the least:

According to the design team, while we cannot give specific numbers [for the three sizes], the breast size has actually changed. In Final Fantasy XIII she had a C cup, now she has a D.

(Editor's Note:  a Japanese D cup is roughly equivalent to an American C, while a Japanese C cup is roughly equivalent to an American B)

That's not the only thing that has changed about the previously rather chaste Lightning, probably in order to raise her popularity. She will be able to wear more than 80 different costumes, and from what we've seen so far, a lot of those show a generous amount of skin, have large slits (Strategically placed, considering that climbing stairs and ledges seems to be big part of the game), vertigo-worthy mini-skirts and thongs strings in sight.

Even the main outfit that has been showcased in most assets for the game is definitely sexy. Besides the form-fitting leather of the front that nicely displays the upgraded bust size, a close inspection of the screenshots show that Lightning's back is left completely (even if tastefully, due to the scarf) naked.

Animated gif from NeoGaf

Further in the interview the host mentioned that he considered the Misty Wizard costume (that you can see above) very sexy. Kitase-san smiled impishly and responded:

The costume is sexy, and the victory pose will change depending on the costume. This one is particularly sexy.

Toriyama-san also mentioned that those that love to show off their own charming Lightning will have no problem doing so, thanks to the ability to customize and recolor costumes and to take screenshots and post them on the Internet.

During a previous stream dedicated to Final Fantasy XIV: A Realm Reborn, Kitase-san also shown a costume reproducing the racial gear of FFXIV's miqo'te (catgirl ears and tail included), that is one of the most revealing sets in the wardrobe coming with Square Enix's new MMORPG.

Those that preferred the original, conservative Lightning should not fret too much, as between the eighty costumes included in the game there are also quite a few that don't show much skin if any, like a full fledged ballroom dress, a butler tux and a male soldier outfit. That said, I can definitely see the heads of a few internet pundits explode over this as soon as they'll catch wind of it. Personally, I don't have a single problem with it, but your mileage may vary.

Below you can see a gallery with a few screenshots and artwork pieces showing a couple of the costumes that have already been revealed, and their revealing nature.