Not only has the film been finished, the DVD is actually coming out tomorrow, January 27th!
looks like it's only available fromhttp://fetishgirls.jp/mai01.html
and not through amazon etc.
There's also a trailer on that website.
I think they nailed the look of Kaede (played by Soaco Roman) and An Koshi as Mai seems alright from the outfits and the acting but I can't help but think they should have dyed her hair. And as expected the trailer doesn't give us any clear idea if they kept the ... controversial third act atrocity for the movie. Since there's an additional character called Miyako (played by Miyako Akane) in the film it's clear they didn't exactly use the manga as the storyboard so we'll see.