I've seen bits and pieces of the Nana films before, and I'm thinking of watching them again for the nostalgia kick. I am aware that there is also an anime adaptation of the manga, which I assume does not cover the entirety of the manga. (The anime ran in 2006, and the manga last published in 2009.)
I've been recommended the anime before (albeit by a friend who had somewhat different taste in this sort of thing), so on the off-chance I end up wanting to watch the anime or read the manga after seeing the film: how much of the manga do the live-action films cover? Are there any major changes to plot or characters that I should be aware of?