Today at the end of the episode for Fate/kaleid liner Prisma Illya 3rei!! it was teased that the series is receiving a movie, there was also a key visual released which can be seen above which was released on the official Twitter for the anime. A video would then follow as an official announcement that the film prolect for the series is underway. The anime series is based off of a original manga which first released September 26th 2007 and ended November 26 2008 with 2 volumes released for it. Its anime adaption aired on June 22nd 2013 and ended September 7th 2013 releasing 10 episodes. A sequel titled Fate/kaleid liner Prisma Illya 2wei would later get released between the dates of July 10th 2014 and September 11th 2014 with 10 episodes releasing for it. There would then be a third season titled Fate/kaleid liner Prisma Illya 2wei Herz started on July 25th 2015 and ended September 26th 2015 with 10 episodes releasing for it. Finally its latest series began on July 6th 2016 and ended September 21st 2016 releasing a total of 12 episodes.
Below is a plot summary for the upcoming new series provided by MAL:
Spin-off of Fate/stay night with Illyasviel von Einzbern as the protagonist, living an alternate life as a school girl. While taking a bath, she stumbles upon Kaleido Stick Ruby, who turns her into a magical girl.