Just in, the movie's plot from the movie flyer ohas been finally translated in english thanks to gustavum of twitter. Be warned though for this may contain some spoilers.And here we go:

"Tomari Shinnosuke is fighting to protect the citizens as Kamen Rider Drive. But one day, a young man appears before Shinnosuke, addressing him as "Father.“





The young man’s name is Tomari Eiji. Eiji has come from the future in order to give a warning to his father: on August 5th, 2015, the Drive Driver (Belt-san) will start to go berserk, which will lead to the Roidmudes conquering the world a year later. Shinnosuke can’t believe it, but just as Eiji foretells, the Drive Driver goes out of control. The widespread destruction it causes leads to Kamen Rider Drive, once the people’s hero, becoming a wanted criminal nationwide.





According to Eiji, the Drive System developed by Professor Krim (Belt-san) was actually a program devised for the purpose of destroying mankind all along. And in the middle of this disaster, a mysterious warrior driving the NexTridoron, Dark Drive, comes from the future in pursuit of Eiji! Mach and Chaser are both defeated by his overwhelming power.





An enemy of unprecedented strength, and an imminent disastrous future… And the partner Shinnosuke has always had fighting alongside him has now become the greatest threat to humanity.



