The story is set in the future on the planet named Amoi which is controlled by a supercomputer named Jupiter. Among the mostly male human population, the light-haired elite class is allowed to temporarily keep the dark-haired "mongrels" as pets. One elite member, Iason, encounters a mongrel named Riki in the slums and decides to take him in. However, Iason keeps Riki longer than it is socially approved, and rumors abound about their possible relationship.

The first episode of "season" one was pre-aired on the Fate Project New Year's Eve TV Special 2020 program.

The Hero has defeated the Demon King, but the Princess he meant to save turned out to be a Prince. NEETdom, here he comes, but a life of relaxation surrounded by anime is a pretty sweet deal. Unfortunately, he gets caught up in millennia old legends, curses, and a twisted plot involving multiple Kingdoms and many dragons. Through and through, though, he'll follow a path of whimsy, even if that involves him palling it up with "villains".

When Gintoki apprehends a movie pirate at a premiere, he checks the camera's footage and finds himself transported to a bleak, post-apocalyptic version of Edo, where a mysterious epidemic called the "White Plague" has ravished the world's population. It turns out that the movie pirate wasn't a pirate after all—it was an android time machine, and Gintoki has been hurtled five years into the future! Shinpachi and Kagura, his Yorozuya cohorts, have had a falling out and are now battle-hardened solo vigilantes and he himself has been missing for years, disappearing without a trace after scribbling a strange message in his journal. Setting out in the disguise given to him by the android time machine, Gintoki haphazardly reunites the Yorozuya team to investigate the White Plague, and soon discovers that the key to saving the future lies in the darkness of his own past. Determined to confront a powerful foe, he makes an important discovery—with a ragtag band of friends and allies at his side, he doesn't have to fight alone. [Written by MAL Rewrite]