While it was the first entry written, chronologically it is the second entry in the series, taking place in the far-future.
After Ryu Shibata wakes up from cryostatis and finds himself in a Bad Future, he's shocked to have found that humanity has driven itself to the corners of death and extinction. In this day and age, humanity is low in numbers, mutants roam the Earth and Killer Robots are ready to cut down the numbers of the survivors at any chance they get. While a few noble civilizations exist, they're ruled by tyrants, or in Ryu's case, an actual cult. Deciding to salvage what's left and ensure humanity blossom anew, Ryu sets out and assembles a Ragtag Bunch of Misfits amongst the survivors he finds, and digs to the root of the scourge that destroyed humanity.
The manga has examples of:
- 100% Heroism Rating: In the final chapter, Ryu, who is now the leader of the town, works on turning Earth habitable with the full backing of his subjects, many of which include his former adversaries.
- After the End: Earth in the future was driven to extinction due to unknown events, but the manga's ending implies that this may no longer be a thing.
- Bad Future: The manga is set in 2038, and it's revealed that Earth has become an apocalyptic wasteland ravaged by multiple wars.
- Babies Ever After: The manga ends with Ryu and Maria having a baby, after their Big Damn Kiss.
- Big Damn Kiss: Ryu and Maria on the cover of an issue
, no less. - Cool Spaceship: Fuji 1, which traveled interstellarly from the fifth planet of Sirius to Earth.
- Crapsack World: Unless you're with Ryu or lucky enough to meet him, chances are you'll starve to death, be killed by murderous machines, be killed by mutants (if not turned into one yourself) or oppressed by the Religion of Evil.
- Creator Thumbprint: It's not a Shotaro Ishinomori story without the government being evil, scummy or involved in a cover-up of sorts. Do note that in real life, he was a noted critic of the Japanese government and it's corruption.
- Cult: The city is ruled by one, and they make the mutants look tame in comparision - even oppressing the mutants themselves.
- Deliberate Values Dissonance:Ryu, after being smacked by Maria: "Women are a problem, no matter the era!"
- Dramatic Irony: This "Ryu" is revered as some sort of hero, while the "Ryu" of the past was seen as cursed because of his white skin.
- Eldritch Abomination: Ryu has to fight off hideous mutants that try to kill him and his friends, and it's implied they wiped out out large swathes of humanity too.
- The Fellowship Has Ended: Averted. The manga ends with Ryu and his friends beginning a full-scale reconstruction of the Earth's world, after defeating Medor.
- Gray And White Morality: Ryu repeatedly has to remind himself not to become as vile as the ones he fights, and even if he is seen as a messiah, he's still subject to criticsm. In his final confrontation with Mendor, he realizes that he isn't an evil bastard like the cult he fought before - he's just as scared as he is.
- Green Aesop: Many chapters stress the importance of looking after nature, and the horrors of what will happen without it. Mind you, people in this setting have to resort to cannibalism because there's nothing to eat.
- Hope Spot: All the remaining, non-mutated survivors see Ryu as a messiah who can potentially turn back the dial of ruin Earth is in.
- Humans Are Bastards: Humans routinely attack one another for supplies, throw their friends under thus bus for power, and Ryu once encounters a human who disrespects Mutumbai and calls him a "four armed freak" even though he's just a child. Ryu becomes really angry upon hearing this and demands he stop.
- Fantastic Racism: Apart from hiding scientific knowledge from the world, the cult that rules the city also oppresses mutants, forcing the remaining ones to go into hiding.
- Humans Are White: Played straight with Maria and Jimmy Henderson. They're amongst the few remaining human survivors, and you can probably guess from their names what races they are.
- Killer Robots: Robot City is protected by hordes of murderous machines that are willing to destroy children as well.
- Official Couple: Ryu and Maria hook up after being separated for a long time. Even if they argued left and right, they truly loved each other, and have a Big Damn Kiss in the finale.
- Only One Name:The only characters with confirmed surnames are the Hendersons.
- Religion of Evil: The cult thrives on oppressing outsiders and deliberately censors history and scientific knowledge to benefit their own goals. They also routinely abuse mutants. That being said not all their followers are bad people and some turn to the light after Ryu shows them the cult's atrocities.
- Shown Their Work: In chapter 27, the manga explains in detail how the ecosystem of nature works and how it slowly decayed until Earth was a husk of it's former self.
- Savage Wolves: Mendor, the final Arc Villain of the manga, repeatedly attacks Ryu with his alwsfor trying to get close to the crystal. And after his death, he bemoans the fact that he had to fight Ryu and mentions that if this another life, they could have been friends.
- Too Dumb to Live: Ryu derides the ape/human beasts as this and says they are a burden to carry. Hearing this, the apes resolve to help Ryu and do better.
- War Is Hell: Before meeting Maria, Jimmy, Peki and Isaac, Ryu curses that humanity has destroyed itself in a foolish war.
