I'd love to help out, but I've not seen the movie and my Google searches don't come up with a picture of the hair that shows enough detail 

Maybe someone else can find a picture to share?

While I don't know exactly how to create that do, a Gibson Girl looks similar to me, maybe you could use it as a basic idea and modify to make it look like your picture.
Also, maybe look for Geisha hairstyles and that may give more authentic ideas.  I know from looking at Geisha wigs that the style in your pic is the most common wig style.  I think they frequently used rats to give a look of fullness to the hair, which was also common in Gibson Girl style.
HTH-Good Luck!!!
PS-I have a sexy Geisha halloween costume from www.howcool.com ; If your hubby's into Japanese stuff he may really dig you in this outfit, it is much cheaper than a real kimono.  (heehee)

I love that style myself however I have to ask ... what is a 'rat'? and where can they be found?

Shoot, I recently saw a site where a woman showed how to make your own rats in different shapes.  You basically stuff a nylon stocking and sew it closed.  She said she used wool as stuffing because her hair adhered to it better.  I'm sorry - I can't find the website tho!

On my first search for hair rat tho, I did find a place that sells them
http://www1.bottomdollar.com/search_attrib.php/page_id=889//

Looks kinda like the geisha style in the pic, no?  Good luck with the costume and let us know if you find anything (it sounds like a good thing to know!)

Cynde