A Wind Named Amnesia (Wind of Amnesia (UK)) (風の名はアムネジア  Kaze no Na wa Amunejia) is an anime movie released on December 22, 1990, based on an original manga by Hideyuki Kikuchi - writer of the popular Vampire Hunter D, Demon City Shinjuku, and Wicked City. The film was directed by Kazuo Yamazaki, of the Urusei Yatsura and Maison Ikkoku fame.

The Apocalypse didn't come with a BANG. Silently, the amnesia wind swept away all of mankind's knowledge. Thousands of years of human civilization vanished overnight as people forgot how to use the tools of modern civilization - who they were - how to speak - everything. Technology decayed as mankind was instantly reduced to level of cavemen.

Now, two years later, a young man explores a nation reduced to barbarism - America. Miraculously re-educated after the cataclysm, he is accompanied by a young woman - somehow spared the obliterating effects of the amnesia wind. Pursued by a relentless killing machine, they search for those responsible for stealing their memories.

Wikipedia