A Wind Named Amnesia

What was left for Humankind after it lost all of it's memories?

A science fiction novel by Hideyuki Kikuchi, A Wind Named Amnesia is a story set After the End...sort of. Three years after losing its memories, humanity has been reduced to an almost savage level, with only but the most basic of instincts now driving the lost and confused humans. Wataru, a young man, travels across America, searching for answers to what happens, and why. Along the way, he meets a girl named Sophia, who tags along with him. As they travel across the country, they witness how society has changed after being stripped of all reason and logic. And it soon becomes apparent that Sophia may hold a secret pertaining to the fall of humanity...

Written in 1983 and later adapted into a film in 1990 of the same name, it was one Kikuchi's many lesser known works (when compared to the more widely known Vampire Hunter D and Wicked City).

Tropes used in A Wind Named Amnesia include:

Amnesia Danger: To put it simply, everything goes to hell the moment everyone awakens and realizes they don't know who they are!
Badass Normal: Wataru, who retains an almost inhuman martial arts skill even after losing his memories.
Big Brother Mentor: Inverted, Wataru is actually much older than Johnny, who is probably 7 or 8 years younger.
Did You Just Punch Out Cthulhu?: Wataru uses a bazooka on a Starfish Alien near the end.
Dystopia: The world isn't entirely in ruins, but without their memories, humanity has abandoned all modern technology and gone back to a simpler, almost cave-man like living style.
Fridge Horror: The idea that pilot of the Town Guardian probably died because his amnesia stripped him of any knowledge of how to operate the machine.
Friend to All Living Things: Tonto.
Her Heart Will Go On: Gender-flipped - Wataru and Sophia have sex, then she disappears.
Humongous Mecha: The Town Guardian GT 7. Even after it's pilot has long since died, it still continues to patrol the Los Angeles area for any crime.
Identity Amnesia: Waturu wonders constantly what kind of person he was before the wind blew, but he believes he was probably the same.
Los Angeles: The setting for a few of the earlier chapters of the story.
Laser-Guided Amnesia: The plot of the story.
Meadow Run: Lisa and Mr. Simpson.
Meaningful Name: Waturu, which means to go from place to another, guess what Waturu spends his time doing.
Mysterious Waif: Sophia
Nightmare Fuel: Plenty of it. From children being left without parents, to possibly former friends and family now killing each other for survival. Giant robots that vaporize anyone for just breathing, and crazed cults formed around construction equipment. Take your pick.
Noble Savage: Quite a few, Little John is one of them.
Older Than They Think: The girl met in the future city near the Mojave Desert is named Lisa Simpson - four years before the premiere of The Simpsons.
Our Monsters Are Weird: Encountered in the sewers of New Orleans, it's confused for a lizard, spider, and snake all rolled into one, with claws, tentacles, and suction cups.
Psychic Powers: Displayed by a crazed patient near the hospital where Waturu meets Johnny. Sophia is shown to have some sort of telepathy.
Reality Warper: Sophia does this in the sewers.
Scenery Porn: From Los Angeles, to Las Vegas, a futuristic utopia, to New Orleans.
Shout-Out: Quite a few.
- 20thCenturyFox is mentioned.
- A portrait of Philip Marlowe and Terry Lennox.
- Mickey Mouse (or at least a crude imitation) can be seen in one of the illustration pages.
Split Personality: The youth met in the Las Vegas strip who is innocent and gentle one moment, but immediately turns into cold blooded killer a the drop of a hat. And the killer personality still retains his memories!
Wise Beyond Their Years: Johnny; however, it's explained he underwent gene therapy that gave him high intelligence, and luckily allowed him to keep his memories.
Woman in White: Sophia again.