Nasuti supports the Troopers throughout their fight against Talpa's forces, though she's got no powers or armor of her own. What she does have is deep knowledge of the mystical armors and ancient artifacts—basically, she's the team's go-to expert on anything magical. She also ends up looking after Ully and gradually becomes like an older sister to the group. Not much is known about her background except that she's half French, half Japanese, and was visiting her grandfather when the invasion hit.
She's 17 at the start of the series, ages to 19 by Gaiden, and reaches her early 20s during the later OVAs. In Kikoutei Densetsu, she plays a crucial role decoding Mukara's mysterious language and manages to get herself and the team to where Ryo and Sage are trapped. By Message, the final OVA, she's in New York attending a UN General Assembly meeting about the strange worldwide events. She only shows up in the last episode, but she's there supporting Ryo as he prepares to face Suzunagi—and the story leaves it unclear whether she actually revealed the Troopers' existence to the world.
There's a fun continuity error with her birthday: Sunrise Animation listed it as May 15, 1970 in one official book (making her a Taurus) but May 28, 1970 in most other merchandise (Gemini, like Seiji). The May 28 date stuck with fans and appears in more official sources. Her surname, Yagyū, comes from a real historical Japanese clan—a naming pattern the series used for most of its cast.
In the manga, Nasuti fills basically the same support role, though her importance gets scaled back to make room for more action. A kid named Jun takes on more prominence instead.
Content compiled by AnimeList.moe from publicly available sources.
