Originally the chairman at Akira's school, she was kidnapped one night by vampires. She was originally a stern, no nonsense human student who was against the idea of having vampires attend the school, seeing them all as evil.
In the beginning, she had a very strong dislike of vampires, like most other humans; however, she becomes tired of having to see Mina leave the school to protect her fellow students. She came to, litteraly, care for her next door neighbor Yuzuru as his parents cared very little for him; both formed a strong sibling-like bond.
After she became a vampire, she became very sexually active, using her body to bring in humans to feed upon. To her own horror, Nanami found herself wanting to rape Yuzuru; becoming a vampire brought her buried true feelings to the surface, albeit intensified. After sneaking into his room and sharing a passionate kiss (which Yuzuru didn't fight off), Nanami came to her senses and fled; she began desiring death to avoid taking his virginity.
When Yuzuru is recruited by Mina to keep her distracted during Hysterica's attack, Nanami is left shocked that he fully reciprocates her romantic feelings. To Nanami's joy, he allows her to turn him into a vampire so they can be together forever. After Yuzuru becomes part of her life again, Nanami appears. to have reverted back to her calm self.
Seen in the anime, Nanami becomes quite upset when Yuzuru is stuck between two of her fellow maids playing volleyball at the pool (primarily because their breasts kept brushing against his head, leaving him flysteted).
Nanami is between the ages of 17 to 18, fairly tall and with pale skin. She has big, green eyes, covered by a pair of oval glasses. She has dark hair with bangs that she parts with help of a pair of hair pins. Nanami is seen mostly with her school uniform; consisting of a white blouse, underneath a red jacket and a black tie. She wears a black mini skirt, below knee-length, black socks and typical brown shoes. Aside from her school uniform, after becoming Mina's servant, she wears a maid outfit.
Nanami is the neighbor of Yuzuru as both of their family is never there as they both have been taking care. She took care of Yuzuru, since his parents didn't took good care of him. Since then, they were often together and treated each other as actual siblings. Her parents are said to be divorced and she stayed home alone a lot, that was until she started to take care of Yuzuru, forming a brother/sister relationship.
However, after staying at school late at night she was attacked by vampires serving a vampire against Mina. She served her because of the Master/Servant bond, but still served the opposition even after her master's death, being blackmailed by her secret love to Yuzuru, a young boy that was her next-door neighbor, to after she became a vampire was unable to control her lust for him, nearly raping him one night. After Mina defeated the enemy and Yuzuru confronted her on her feelings, he willingly becomes a vampire so he could live in the Bund with her. She later returns to her position as Student Council President, though in the omake reveals she also became one of Mina's maids. It is noted that she has a very keen eye for detail, noticing how the school was built to house vampires after discovering that Mina was the Chairwoman/Founder of the school (however this only happened in the anime, in the manga it was Mina who pointed this out). The maids refer to her as a shotacon after seeing Yuzuru.
- Nanami is shown to regret her actions as a vampire, prior to Yuzuru letting her to him into one, suggesting that any vampire who acts like some kinda deviant isn't fully in control of themselves.