The title is 劇場版プリパラ み～んなでかがやけ！キラリン☆スターライブ！ Which I believe translates to "PriPara Everyone Shine! Sparkling☆Star Live" or smth idk if someone has a better translation let us know xD It will be released 4th March 2017.
I honestly don't get the plot but it looks like Laala and friends go on a "Puchū Tour" to check out the history of PriPara. They tour around the solar system to spread the word about how wonderful PriPara is, but challenges await on each planet.
I have no idea how many "friends" that is, but hopefully Hibiki, Ajimi and NonSugar (maybe even Triangle???) get some spotlight and there are no "sides" like poor Hibiki was in the PriPari movie ;-; Hey maybe even some Cosmo since this is focused on space xD
But then again I'm sure there are better translators than me out there so here's the link: http://news.mynavi.jp/news/2016/10/29/127/
Anyways, it honestly doesn't sound like too much right now maybe it's because I never liked history class in school xD but hey maybe once they reveal more about it and maybe even pictures I'll start liking it more?
P.S. I'm not sure but I'm pretty sure "Puchū" tour is a pun on PriPara and space (uchū) xD