Nanami is beautiful and popular freshman at Ohtori Academy. She is also wealthy and carries a prestigious last name. Her older brother is none other than Touga Kiryuu, the president of the Student Council. It would seem that Nanami fits the traditional stereotype of a young rich girl perfectly - she is a spoiled brat. However, there is far more to Nanami than a little girl who just has to have her way all the time . . .

Nanami Kiryuu is used to getting her own way. Like Touga, she cannot stand to have what she wants denied to her. Also like Touga, she uses her natural charsima to manipulate those around her. She has no less than seven loyal henchmen in the series. She is also highly intelligent, and is constantly scheming ways to get rid of her enemies. Despite her intellect, Nanami tends to be a melodramatic drama queen at times.

Nanami adores her older brother Touga. Really adores him. Really, really adores him. Nanami is extremely jealous of any girl who catches her big brother's eye, and for that reason hates Anthy and Utena. Nanami employs her henchmen and her own intellect in numerous schemes to get rid of Anthy and Utena. Her love for Touga, however, does not extend towards sexual feelings (as we are led to believe throughout the majority of the series.) Only towards the very end does Nanami prove that she loves her brother . . .but not in that way . . .

Nanami is cursed with unusually bad luck involving animals. In the first ten episodes alone, she is attacked by a mongoose, a hoard of snails, a horse, a bull, a boxing kangeroo, and a herd of elephants. She is also attacked by a giant inflatable squid, if you count that as an animal. This curse, along with Nanami's tendency to over-react to everything, makes Nanami an ideal candidate to provide most of the comic relief in the series.

However, not everything involving Nanami is humorous. When she finally becomes a Duelist and fights against Utena, she reveals a great amount of supressed rage. She is angry at Utena for stealing her brother's affections, she is angry at herself for not being able to always please her brother, she is angry at the world for all the injustice it has thrown at her. The ironic thing is that most of the injustice is imagined. Nanami is popular, rich, young and beautiful - she just doesn't know how to count her blessings. In the end, Nanami is unable to see past what she wants but doesn't have, and therefore cannot enjoy what she already has.