A bride lies gravely wounded on her wedding day, the victim of a brutal assassination attempt by her former colleagues, an elite group of assassins known as the Deadly Viper Assassination Squad, and their enigmatic leader, Bill. Left for dead with a bullet in her head, she falls into a deep coma. Upon awakening four years later, she discovers she has lost her unborn child in the attack. Consumed by an insatiable desire for revenge, she sets out to exact vengeance on those responsible, crafting a list of names to hunt down one by one.

Her journey of retaliation leads her first to Pasadena, where she confronts Vernita Green, now living a suburban life far removed from her past as an assassin. From there, she travels to Okinawa to seek a master swordsmith, who forges a unique sword for her quest. With her new weapon in hand, she heads to Tokyo to face O-Ren Ishii, another member of the Viper Squad who has become a powerful yakuza boss. As she slices through O-Ren's underlings, the stage is set for a fierce face-off, and her crusade for justice pushes forward, driven by the unchecked fury of a woman scorned.