Nagisa is the main protagonist who suddenly transfers to an all-girls school called St. Miator Girl’s Academy. The reason she transferred is because her parents went overseas for work, leaving Nagisa behind. Nagisa ended up transferring to Miator after her aunt, who is a past graduate of St. Miator, the oldest school of Astraea Hill, recommended she attend.
She seems to have a peppy personality, which can usually cause her to get in trouble if it gets the best of her. This trait is apparently quite distinguishing, as Amane Ohtori from Spica had commented that the other Miator students remind her of “caged birds”, but that Nagisa is extraordinarily different. One might theorize that she is one of few Miator students not deeply enmeshed in that school’s traditions and customs and therefore more free-spirited and more likely to act according to her own impulses, rather than according to expected patterns. She certainly has a gift for energizing her surroundings and the people around her. From their first meeting on, Nagisa gradually develops a strong attraction towards Shizuma; the Etoile may very well be Nagisa’s first love.
Other things about her include that Nagisa is easily frightened, making her tremble at even the slightest mention of something scary, especially ghosts. This continues the theme that she tends to be more childish than most of the rest of the students her age. She has a large appetite, especially for sweet foods. Also, she admires others for their artistic abilities. She herself has displayed an aptitude for acting and the piano, both nurtured through interaction with Shizuma. She is a fairly talented actress, being able to take over the lead role of Carmen when Chikaru is injured. Her weakness is French, for which she requires tutoring from Tamao and Shizuma.
Nagisa bears a striking resemblance to Shizuma’s deceased Etoile partner, Kaori Sakuragi. The only difference are their hair colors (Kaori’s is black, while Nagisa’s is red) and Kaori’s pale skin.