After both her parents died, she was adopted by a Shinto priest and chosen to inherit the shrine duties. Her upbringing has left her honest and self-sacrificing, but also fatalistic and resigned to the vicissitudes of fate.
Nanami was adopted from an orphanage by a Shinto priest from Hai-Lan whose own daughter, Minayo, was stillborn. She is a dutiful, respectful girl who is anxious to do well. Since Shinto tradition places a heavy emphasis on family and ancestors, only a direct descendant can be accepted as a protector of the family shrine. As the only child in the family, Nanami's duty is to perform a ritual to be accepted by the shrine's resident spirit. This ritual apparently consists of sending her to retrieve the Dragonbane sword from its resting place in another shrine within the Dragoncastle Caverns, a series of underground tunnels situated North of Hai-Lan. She has attempted it at least once before, but has failed. Undaunted, she decides to try again, in spite of her parents' apprehension, and, before setting out, prays to Minayo's spirit to grant her strength. On her way through the Caverns, she reflects on her decision. She strongly feels her position as the "wrong" daughter, but nevertheless wishes to prove that there is more to a family bond than blood, and that she can go through the ritual based only on her own merit, rather than on her lineage.
As she approaches the Dragonbane sword, Minayo's spirit appears and attacks her. Sensing this, Lenneth intercedes to defend her. However, Nanami sees that Minayo has not accepted her death, or the fact that she is trying to take her place. This grieves her deeply, more than Minayo herself, because she realizes that, try as she may, she will always be the "wrong" daughter in one way or another. She admits that she does not want to die, but feels that the only solution is to trade her life for Minayo's, allowing her to live on in her body. Lenneth recruits her, and Minayo returns to her parents with the Dragonbane. Despite her appearance, they understand that she is not Nanami and grieve.
If Lenneth revisits the shrine after recruiting Nanami, Minayo will give her the Dragonbane as thanks, saying that she will never forget Nanami's sacrifice.
Nanami is one of the first Sorceresses you can obtain and comes with two attack spells and one restorative spell. She is slightly stronger than Jelanda, and her usefulness is heightened by the Dragonbane, which, despite not being unique to her and lacking Great Magic, is one of the most powerful Sorcerer weapons in the early game. Otherwise, her stats are identical to Yumei's, barring her elemental tolerance. Her Familiar is a dove.
As Nanami is a Sorceress, her PWS will vary depending on her assigned attack spell and her weapon. She will either cast the same spell three times in a row or use Great Magic, if her staff has that property. She will say "Tenchu! Punishment from the Heavens!" before using it.
Nanami is one of the characters whose recruitment is randomized. She may appear in Hai-Lan in Chapter 2, 3 or 4, on all difficulties.
Nanami's starting hero value is -85, which is rather low, but she can meet the requirements for Chapter 3, 4 and 7.
Nanami is a common Japanese name. However, the game uses an uncommon spelling, which is a composite of 那 (na; either "which" or a form of emphasis) , 々 (a symbol of repetition)  and 美 (mi; beautiful) . Thus the entire name could mean "that which is beautiful" or "very beautiful", if 那 is used as an emphasis. It is interesting to note that Minayo's name is actually a quasi-mirror image of Nanami's: it uses two of the same characters: 美 (mi) and 那 (na), with the addition of 代 (yo; to replace) , which refers to the fact that Minayo takes Nanami's place (after Nanami herself tried to take her place).
- Nanami is voiced by the same actress as Yumei, Llewelyn, Shiho, Celia, Lemia and Claire.
- When you return to the shrine to obtain the Dragonbane, Minayo will address the party as "honored parents" . This line may have been intended for the scene where she returns from the shrine instead of Nanami, and thus appears to be an oversight.
- According to the developers, Nanami's sacrifice is actually a form of Soul Transfer, much as what Belenus did for Asaka or Lemia for Grey. As Minayo was stillborn, she never had an adult body, which is why Nanami was able to offer her own.