OVA
Description
Nasuti Yagyū is the granddaughter of Professor Konosuke Yagyū, a historian specializing in legendary armors and the Youja threat. She assists him at the university, sharing his extensive knowledge of mystical armors and ancient artifacts. Her expertise proves vital to the five warriors opposing the Dynasty's forces.

Born to a Japanese father and a French mother, Nasuti was raised in France before returning to Japan. Seventeen years old at the series' start, she possesses a French International Driver's License and operates her Mitsubishi Pajero Sport Turbo, essential for transporting the group across Japan. Her typical fieldwork attire with her grandfather consists of culottes and skirts, chosen for comfort and mobility.

Learning of the Youja World's invasion, Nasuti travels alone to Shinjuku, encountering the five warriors and a young boy. She becomes their guardian, leveraging her academic knowledge to guide them. After her grandfather is killed in her arms during the conflict, she channels her grief into supporting the warriors. She provides them refuge at her family’s vacation home, a sanctuary offering emotional respite and a symbol of normalcy.

Her technical skills are indispensable; she uses her computer and her grandfather’s archived files to locate the warriors after their initial defeat and separation. Though captured multiple times early on, she adapts by avoiding direct confrontations. Notably, she and Jun remain uncorrupted by the Youja World due to their lack of greed or malice, a purity that later empowers the Inochi no Magatama artifact.

Later, in *Gaiden* after Talpa’s initial defeat, Nasuti participates in Ryo’s birthday celebration. When news reports indicate Sage’s Halo armor is being used by a killer in New York, she accompanies the group to investigate. They confront the sorcerer Shikaisen, who has captured Sage and weaponized his armor. In *Kikoutei Densetsu*, now aged 19, Nasuti deciphers the language of the new antagonist Mukara, enabling the group to locate Ryo and Sage. By *Message*, in her early 20s, she attends a United Nations General Assembly session addressing global threats, intending to disclose the warriors’ existence to world leaders, though the outcome is unconfirmed.

Her surname references the historical Yagyū clan, aligning with the series’ use of real Japanese lineages. Conflicting sources list her birthdate as either May 15 or May 28, 1970; the latter is more widely accepted. Her hobbies include driving, studying legends, and recent kendo practice.