It takes place in a western/steampunk setting, primarily on a fictional desert planet where humanity has settled after leaving Earth, where civilization is sparse and mostly lawless.
The series' story follows the adventures of Vash the Stampede, a legendary gunman who aims to spread his message of love and peace while combating his brother Millions Knives and Legato Bluesummers.
The protagonist of the series is Vash, a jovial, pacifist gunman who is followed by disaster and misfortune due to the large bounty on his head.
Early on in the series, he is pursued by Meryl Stryfe and Milly Thompson, insurance agents assigned with evaluating damages involving him.
Closely following Knives is Legato Bluesummers, a cold and powerful man who is the leader of the Gung-Ho Guns, a group of super-powered assassins.
He and his brother, Knives, were born on a colony ship that was part of a fleet sent to find and settle a new world to extend the human race.
Initially, Meryl and Milly, representatives from an insurance agency investigating claims made due to damages the "Humanoid Typhoon" caused, find him as bandits are hunting him down to collect the bounty on "The $$60,000,000,000 (sixty billion double dollar) Man".
Vash is frequently injured as a result of refusing to kill his opponents, causing him to have several large scars and chunks of missing flesh supported by metal mesh on his body.
Vash says his full name is Valentinez Alkalinella Xifax Sicidabohertz Gombigobilla Blue Stradivari Talentrent Pierre Andri Charton-Haymoss Ivanovici Baldeus George Doitzel Kaiser III, but this may just be another joke.
In the anime, it is depicted as a modified version of the Dan Wesson ppc 357, which Knives created to fuse with Vash and transform into the "Angel Arm".
Vash later gains better control over his powers, forming smaller cannons and defensive feathers, though his hair continues to darken until it becomes almost completely black.
In the manga, she becomes frightened upon discovering Vash's true nature as a Plant, but later comes to understand his past after seeing his childhood memories and of the destruction of July through his eyes.
Millions Knives (ミリオンズ・ナイブズ, Mirionzu Naibuzu) is the main antagonist of the Trigun manga and anime and Vash's twin brother, who is one of the few fully sentient Plants.
As he absorbs more Plants, his Ark takes on the form of a sentient organism, capable of defending itself and, in some cases, teleporting short distances.
He gives Vash a case and each Gung-Ho Gun a half coin to place into it, stating that "something interesting will happen" after it is completed.
He explains that if Vash can reassemble all twelve coins, something interesting will happen; when they later fight, it revealed that the filled case can block Legato's powers.
Monev the Gale was hired as an assassin to fight Vash; to make him strong enough to do so, Knives locked him in a cell to train his body for twenty years.
Dominique the Cyclops has an ability called the "Demon's Eye", which causes hypnosis and sensory paralysis in her foes, momentarily stunning them and making her movements appear to be immediate.
The anime does not feature his background, and he is simply an assassin who can use his puppets to do various tasks, such as delivering reports to Legato and spying on and attacking people.
Wolfwood kills him by shooting out a pipeline filled with corrosive liquid, melting his armor and exposing his brain and internal frame, before destroying his upper body using the Cross Punisher.
Hoppered the Gauntlet is a masked man who wears a set of armor to cover his degenerated and vestigial legs while using his arms to move.
During his final battle, he sees Vash's memory of July, realizes he made the wrong choice, and is killed after turning against the Guns.
In the anime, Zazie is a demon who possessed the body of Bete, a troubled young boy who can control sand-worms using a high-frequency device he wears on his head.
Midvalley the Hornfreak is a violent musician who can use his tenor saxophone to generate destructive sound and play frequencies that drive those that hear it into a murderous frenzy.
In the anime, Midvalley plays Sylvia, a cross between an alto and a tenor saxophone, who serves mainly as Legato's bodyguard before becoming the final Gun to fight Vash.
Vash damages his horn, rendering him unable to play, and Midvalley commits suicide by triggering the machine guns hidden in the bell to backfire into his chest.
Simply known as "Chapel" in the manga and also known as 'Master C', he is a member of the "Eye of Michael", an organization of ecclesiastical assassins founded by a church that worships Plants.
Despite being middle-aged, like other members of the Eye, the artificial modifications made to his body, which grant him enhanced strength and reflexes and regenerative abilities, have aged him considerably.
When Livio fights against Elendira and is unable to win, he allows Razlo to awake and help him kill her by utilizing his faster reflexes and better eyesight.
"[citation needed] In Trigun Maximum, Kuroneko-sama only appears in Nightow's commentary at the end of each issue, often criticizing his lazy and silly nature.