Metal Max Xeno takes place in the former location of Tokyo Bay, now a desert referred to as Distokio by its inhabitants, approximately a century after the "Great Annihilation" in which the supercomputer NOA attempted to destroy human civilization in order to prevent further ecological disasters.

NOA is eventually defeated, but with its final moments it sends an order to its creations, colloquially known as "SoNs", to completely exterminate humanity, thus beginning a second genocidal campaign.

Iron Base is visited by a young man with a metal arm (the player character, default name "Talis"), who announces his intentions to destroy the SoNs with his tank in revenge for their attack on his hometown and subsequent deaths of his mother and adopted father.

Talis finds no survivors in the ruined settlements, but, following an encounter with a large spider-like SoN, he rescues Toni, a former resident of Iron Town and the crush of Yokky, who had believed her to be dead.

Yokky joins Talis in searching for survivors and the two encounter Dylan, the former leader of a bandit gang that had harassed Iron Town in the past, and save him from a tank hacked by the SoNs.

He is taken back to the Iron Base, where he is reluctantly allowed to stay and recover, and Toni joins Yokky and Talis as they travel north to locate new survivors.

The next morning, Po-M reveals that data recovered from the library indicated the existence of "Cherbourg", a massive defense shield that could protect Iron Base from SoNs attacks.

Po-M nicknames the SoN "Catastropus" and identifies it as the one responsible for the destruction of the other settlements in Distokio, but warns that it is too powerful for Talis to confront at his current strength.

Upon waking, the girl, named Ittica, goes with Talis back to Iron Base, and later reveals that she is a genetically engineered human-animal hybrid called a "Mute" which possesses the ability to shapeshift.

Yokky and Toni, with the assistance of Maria and Ittica respectively, come to terms with their feelings and insecurity, and the citizens of Iron Base steel themselves in preparation for the final battle.

Yokky joins him, and after getting a farewell from the citizens of Iron Base and a promise that they will always be a home for them to return to, the two depart in the tank Talis originally arrived in.

When Toni is discovered to be alive, he quits drinking and romantically pursues her again, but his shyness and lack of experience in girls causes his feelings to go unrequited.

He is possessed of a brash, crude demeanor, often coming into conflict with the calmer members of the team, but he does appreciate the second chance he was given, and fights loyally by Talis' side.

He is usually polite, calm, and mild-mannered, preferring only to get into a fight when absolutely necessary, but he is not afraid to speak out against those who irritate him, namely Dylan, whose crude manners and boisterous attitude often conflict with his quiet nature.

Referred to as an "immortal" soldier, her actual age is unknown, but she has been alive since the destruction of U-Tokio several decades ago, and has lived in the repository since, defending it from besieging SoNs.

U-Tokio was destroyed when a failed military operation to retake sectors of the surface allowed for the SoNs to access the tunnels, and now only exists as ruins.

NOA: A massive, hyper-intelligent supercomputer developed by Vlad Corp in order to solve the issue of mounting ecological disasters plaguing humanity.

Metal Max Xeno was first teased in October 2017 via a trailer published by PlayStation Official YouTube channel with the subtitle "True End of Century, Born".

[7] A remake of the game with enhanced visuals, an ATB system, and altered vehicle physics titled Metal Max Xeno: Reborn was released in Japan for Nintendo Switch and PlayStation 4 on 10 September 2020.