If you've seen the original anime (and if you haven't go watch it right now before you read this review), then you're familiar with the story and it's resolution, so I'll spare the summary. The actual movie itself takes place roughly a year after Menma's wish has been granted, and catches up with the rest of the Super Peace Busters as they gather together to write their own letters to Menma, sharing their thoughts and feelings about what she meant to them and how they're doing now that she's gone.
Using this premise, the show switches back and forth between three different perspectives. The first of these are scenes from when the Super Peace Busters were children, and how they welcomed Menma to their group and played around. From there, we follow the characters writing their letters in the present, preparing for a celebration of sorts for their departed friend. And using that as a springboard, we see flashbacks to events from the actual show, as the process of writing the letters brings them back to the surface.
The problem with the movie is not so much anything to do with it's characters, story, poor writing, or what have you. Simply put, it suffers from a lack of new content - while maybe half the movie features new scenes (both in the show's present and past), the greater part of it consists of flashbacks and scenes from the original anime. Put together with how often the perspective changes, the result often feels disjointed and slightly unfocused.
What AnoHana: Letters to Menma does well, however, is provide a little more closure for fans of the anime. Getting to see the Super Peace Busters playing around as children was priceless, and certain scenes even add even more emotional gravitas to the show's powerful ending. That's a tricky feat for something as well written and self-contained as AnoHana - one wrong move and you risk looking revisionist or retroactively harming the story's original impact. And while there wasn't much development during the scenes set in the present, getting to catch up with the characters a year later felt a little like revisiting old friends and was rewarding in it's own way.
When all is said and done, this is a good movie. It's not without it's problems, and it's not one you should watch without seeing the show first, but it serves nicely as a sort of 'where are they now' and does a fine job of adding additional back story without damaging the integrity of the original show. If you're already a fan of the show, there's nothing you can lose from watching this movie.
