- “It's not like I get a complete picture. More like, looking through a keyhole. All I can see is one part of person's life - their death.”
When she was 5 years old, Yukio predicted her own parents' death and they soon died in a car accident. She was orphaned until she was discovered by Ichirō Yashida, who had taken his granddaughter Mariko on a trip to view a factory he was opening in the south of Japan. From then on, she was raised by the Yashida family as Mariko's adopted sister and trained as her protector.
- “You are a soldier, and seek what all soldiers do. An honorable death - an end to your pain.”
After Yashida realizes he is dying, he instructs Yukio to travel the world to find Logan and bring him to Japan. She finds him a nomad living aimlessly in Yukon, Canada, and persuades him to travel to Japan for one day to meet Yashida. Yukio is present at Yashida's funeral ceremony alongside Logan, where the Yakuza attack and attempt to capture her sister Mariko.
Yukio then has a vision of Logan's death. She goes to warn him but is too late as Mariko is captured by the Yakuza who are revealed to be hired by Mariko's fiance and the corrupt Chief of Justice Noburo Mori. Logan and Yukio arrive at Yashida Family Home, where he finds the parasite on his heart, similar to the one inside Yashida's body. He attempts to use his claws to extract it, when Shingen enters mid-procedure and Yukio defends Logan.
Yukio is knocked unconscious by Shingen. Logan briefly dies in the process, but regains his healing ability to fight Shingen. Although he initially leaves Shingen to live with the truth that he ordered his own daughter to die, Logan kills Shingen with his claws after the latter tries to attack him in anger. Yukio and Logan then follow Harada and Viper to the research center to find Mariko. When he arrives, Logan is attacked by Harada and the Yashida family's Black Clan. Logan is subdued by a combination of the Black Clan's arrows and a substance concocted by Viper to weaken Logan as Yukio is helpless to watch.
After Logan is put in a restraining device, Yukio comes to his defense and fights Viper while he fights the Silver Samurai. Yukio kills Viper by hanging her in an elevator shaft.
Wolverine later boards a plane with Yukio, who reminds him that she is still his bodyguard, and offers to fly him anywhere in the world.
Powers, Abilities, & Weaknesses
- Death Sense - Yukio is a mutant with a limited, precognitive ability to discern the nature of a person's death. Such visions, when and if they occur at all, have a high degree of accuracy.
- Enhanced Agility - Yukio is an accomplished gymnast in disciplines of tumbling and somersaulting. She combines these talents with her swordplay to provide much of her defensive action in combat.
- Master Martial Artist - Being a Japanese assasin, Yukio is highly skilled in martial arts and hand-to-hand combat, either unarmed or combined with her sword or her staff.
- Master Swordswoman - Yukio possesses great proficiency in swordsmanship. She ha shown being able to go on par with Shingen Yashida, a highly proficient swordsman, for an extended period of time.
- Master Assassin - Yukio has been heavily trained in the art of assassination techniques.
- Clinical Deaths - It is possible Yukio's powers can't perceive clinical death. She rarely misinterpets the forseeable future of one person's life. However, she failed once, thinking that Wolverine was going to die because she saw him holding his heart. Wolverine was clinically dead and was healed after removing the parasite that was in his body suppressing the mutant's healing factor, before he could enter brain death.
- False Deaths - Yukio cannot foresee faked deaths, such as that Ichirō Yashida.
- Katana Sword - Yukio has a sword named Danzan (meaning "separator" in Japanese). The sword is over a hundred years old and can cut through most materials with ease.
- In the comics, Yukio is human and not a mutant.
- Another deference in the movie is that Yukio has red hair. In the comics, she has black hair. Also in the comics, she has an infatuation with Logan, going as far as trying to have sex on train tracks. While in the film, she has no desire for Logan.
- She directly foreshadows the ending to Logan, when she says "I see you on your back, there's blood everywhere...and you're holding your heart in your hand."