A fourth-year student and Etoile candidate in St. Miator Academy.
She has an optimistic personality, which can usually causes her to get along with everyone she meets. She has a talent for causing trouble, which at the strict all girls school doesn't amount to anything serious. 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. At first, whenever Nagisa gazed into the eyes of Shizuma Hanazono, she was unable to move, as if paralyzed. Later on, she develops a strong attraction towards Shizuma, who is the Etoile and a very popular person within the school.
Other things about her include that Nagisa is easily frightened, making her tremble at even the slightest mention of something scary. 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. This talent for Piano is displayed in a very touching scene in which Shizuma and her make an emotional connection, and play the song A maiden's Prayer. 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 Miyuki and Shizuma, which I suspect is an attempt to spend more time with Shizuma.
Overall she is a very likable character, and is a great central piece to an anime that has long been described as the gateway to yuri. She like most of the character in the anime is very emotional, which is to be expected. She is a kind soul, and very fun to watch as she goes through life. There are no men in this series at all, which means Nagisa is surrounded by constant drama, which is rather addicting yet so precious.