As a youth, Harada mastered the attendant disciplines of the medieval samurai and sought employment as a warrior for hire. He first worked for the criminal Mandrill and clashed with the blind hero Daredevil.
Following his father’s death, Harada sought the leadership of Shingen's Clan Yashida from his half-sister Mariko Yashida. but was opposed by the Ronin Yukio and Mariko’s lover, the mutant adventurer Wolverine.
Silver Samurai ends up fighting the New Mutants again.
Later, Harada worked with Wolverine to free American private investigator Jessica Drew from the influence of Black Blade of Muramasa, a sword mystically imbued with its creator’s madness.Wolverine himself fell under the sword’s spell, but managed to overcome his possession after which Harada took up the sword, finding himself worthy of its power.
After Mariko’s death, Harada claimed leadership of Clan Yashida.
The Samurai even once helped Wolverine destroy the monster known as Doombringer.
Big Hero 6
He was briefly employed by the Japanese government as leader of their fledgling super-team Big Hero 6.  He joined to prevent Everwraith from slaughtering millions in downtown Tokyo. During the battle, Big Hero 6 was joined by Sunfire, Japan's premiere super hero and a mutant with the ability to super-heat matter into plasma, who was instrumental in the Everwraith's defeat.
Soon after, Big Hero 6 moved their headquarters from the Giri Office Building to Japan's Cool World Amusement Park, where they were attacked by X the Unknowable, a monster born from a child's drawings that could transform its atomic structure into any form and shape. With the help of Alpha Flight, Big Hero 6 destroyed X the Unknowable in the fires of Mount Fuji. Afterwards, Big Hero 6 continued to protect Japan from all threats, such as when the team rescued Tokyo residents from a freak blizzard caused by the Crimson Cowl (Justine Hammer) and her Masters of Evil.
Ultimately, his inability to lead Clan Yashida allowed the Mongolian crimelord Haan Kaishek to take control, and he allied with Wolverine to defeat the Kaishek’s. However, the disgrace of losing leadership was too great for Harada, and he returned to his mercenary ways.
Eventually falling into the service of Hydra once more, Harada was dispatched to battle the female ninja Elektra and was seemingly killed.
Revealed to have survived, the Silver Samurai resumed his criminal career following an encounter with the mutant Blindspot. Allied with known terrorist Lady Deathstrike, Harada attempted to establish himself as the "Silver Shogun," leader of the Yakuza.
He was also briefly a prisoner in The Raft as part of a super-villain stockpiling conspiracy.He was freed by Madame Hydra and the Hand, who transported him back to Japan.  They wanted him to lead the Hand and to unite the criminal underworld, hoping he could take on shadowy figures controlling both Hydra and S.H.I.E.L.D. that Madame Hydra was reluctant to name. Samurai wasn't interested in a conflict and helped the Avengers defeat them.  Later, Samurai began operating as the chief security officer for the Prime Minister of Japan. 
Silver Samurai was recently brainwashed by the mutant Blindspot into forgetting his time as a hero, believing his redemption was just a result of Professor X's brainwashing. As a result, he had returned to his previous criminal activities.
Wolverine made his way to Japan in search of Harada and engaged him in battle. Wolverine had recovered all of his memories due to the events of House of M and asked the Samurai questions about his past during the course of their fight. The Silver Samurai was able to run Wolverine through with one of his swords, however Wolverine grabbed the Samurai by his right forearm and severed his hand at the wrist with his claws, leaving the Samurai kneeling on the floor cradling the bloody stump where his hand once was.
After the Skrull Invasion, Viper left Samurai to rejoin Hydra. She returned with a new Madame Hydra to negotiate support to be given to Typhon, Hydra's production front, from the Clan Yashida. Also, they took a mysterious box; the Clan Yashida claimed that those who opened it never lived to see another day.Some time later, warriors of Leviathan attacked the Samurai to make him reveal the location of the box.
Wolverine in Hell
When the Red Right Hand sent Wolverine to Hell, they also sent an army to kill his friends, Harada being one of them. Harada bent over with arrows piercing his armor. He was stabbed in the chest as the Yashida Stronghold burned behind him. He limped to his sister Mariko Yashida's grave and died.
He was brought before Logan and the Devil in Hell. The Devil chopped Harada's head off with the Soulcutter and proceeded to slice his body up. The wounds of the Soulcutter could never be healed.
Tachyon Field: Ability to generate a tachyon energy field from within his body. Though he can focus this energy through anything, he typically focuses this field through his sword; allowing it to cut through almost any substance.
The Silver Samurai is a master of Kenjutsu, the art of wielding a katana, and is an expert in the art of Bushido, the history and customs of the samurai class. He is also a highly skilled grandmaster of the Japanese martial arts such as Jujutsu/Aikijujutsu, Karate Do, Bujutsu, Kenjutsu, Iaijutsu, Tantojutsu(knife-fighting), Ninjutsu, Kyujutsu(Samurai Archery on or off horsback), Bajutsu(horsemanship), and Samurai strategy and tactics although his abilities do not quite match those of Iron Fist or Shang-Chi despite the fact that both the latter are versed in Chinese martial arts.
The Samurai's teleportation ring was originally obtained from John Belushi in Marvel Team-Up #74, in which Spider-Man teamed with the 1974 cast of Saturday Night Live. This has remained in continuity, although recent references have replaced Belushi with Chris Farley.
The name "Keniuchio" does not exist in the Japanese language. As a result, the Silver Samurai's name is often rendered in Japanese media as Ken'ichirou Harada (原田剣一郎 Harada Ken'ichirō).
Silver Samurai's early appearances are reprinted in X-Men Classics.