The world is swept by a new mysterious disease that turns people into stone. Since no cure could be found, scientists started a programm to save humankind by putting a group of people into cryogenic stasis until they eventually will find a cure.
But after waking up - the survivors realize that the scientists plan has failed and dangerous creatures now roam in the meant to be safe secret retreat.
As usual in japanese sci-fi stories it will get more complicated and results in a mind blowing finale. A ending you would not have seen coming.
It might not be on the same level of Neon Genesis Evangelion but it is one of the very few movies of the genre that really made a lasting impression on me.