Nasuti Yagyuu

Nasuti aids the Troopers during their quest against the forces of evil. Not much is known about her past, except that she is half French and half Japanese, and was visiting her grandfather when Talpa's invasion began. Unlike her friends, Nasuti has no super powers or weapons. However, she is extremely knowledgeable about the mystical armors and various ancient artifacts. She provides vital information to the Troopers and acts as a caretaker for Ully. Over time, Nasuti becomes like an older sister to them.

In the beginning of the TV series, Nasuti is 17 years old. In Gaiden, she is 19 years old. During Kikoutei Densetsu (The Legend of the Inferno Armor) and Message she is in her early 20s. Nasuti's birthday technically falls on two dates, due to an error made by her creators at Sunrise Animation Studio. According to the YST book, Memorials, her birthday is listed on May 15, 1970. However, according to many other official YST merchandise, her birthday is listed as May 28, 1970. Both official books were compiled by Sunrise; however, the latter date is often used in other official documents.

During Kikoutei Densetsu, Nasuti was crucial in aiding the Troopers in decoding the mysterious language used by Mukara; and she was able to take herself and her friends to where Ryo and Sage were located. In the 3rd and last OVA, Message, Nasuti was in New York City, where she was attending a special session of the United Nations General Assembly that was convened by the United Nations Security Council to solve the recent, bizarre events that have been happening worldwide; which was seen as a threat to international peace and security. During the meeting, Nasuti planned on telling the world officials about the existence of the Troopers. Whether she succeeded in doing so remains a mystery.