No, this isn't something Phoenix Wright uses, but it's close.
From Comiket 83, these appear to have been extras if you bought the special novel. I remember something like this, several years ago I was impressed with how much anime stationary they can make, you'd think students would like to show off their otaku'ness. These are the equivalent of the manila folder, only that they are plastic and part see-through. By the way, the above file folder seems to be actually one piece.
I admit I'm posting this in part to ask anyone who owns these, if you can scan them or at least take a great centered pic of them, specifically the Houki/Rinny one, these have not hit the world widened web yet (as far as my ruined internet access has shown me), as Houki's husbando I must have this pic, her pose, those big ones, and that green-bow-in-her-hair-that-she-is-using-because-was-has-yet-to-be-defiled-by-Ichika, in fact all the girls are great in this, but the Houki shot, I NEED HER NOW XD
Come on, spend that 6000Yen and you can get a bag emblazoned with the girls in their above poses!