" Shuichi, you look so cute . . . . you are to me just like a cute little sister ! "---Anna
Throughout the series, Anna first comes off as a cold and disinterested, but necessarily sociable, person. She is first introduced as a friend of Maho Nitori, Nitori Shuichi's older sister, and also a model at the same agency as Maho. She is considered outspoken and sharp-tongued by other teen models. She shares the same group of friends as Maho and is often seen at the Nitori household, encountering Shuichi often. Initially disgusted with Shuichi's supposed "cross-dressing", she states that it is, in a fashion sense, weak at best. But she soon grows accustomed to it, and later says that Shuichi's female fashion style suits her.
Anna has contrasting personalities on many levels. She can be outgoing and amiable when out in public, or at a photo shoot. However, simultaneously, she can be introverted and fearful when among strangers, unwilling to be friendly or to be at ease socially. It is also revealed that she has a cool and calculating demeanor, but that, in reality, is a misnomer, as she is underneath a kind and loving person. However, her perceived coolness and demur projected from the outside comes off as scaring away both girls and boys alike. She has a affinity towards "weird" things and declares that some things that are not normally seen as cute, are actually cute in her mind.
Surprisingly, when Shuichi shows Anna a degree of attention and kindness, she reciprocates, and they quietly begin dating. As Shuichi's problems with being their correct gender mount up, Anna at first backs away in fear, unable to offer any compassion. However, Anna's strong sense of loyalty to Shuichi wins out, and she not only resumes dating Shuichi, but tells them that she will always be by their side, both before, during, and after their transition to that of a teenage female.
Anna's Story (Anime)
Anna is a very attractive teen model, who is a good friend of Maiko and goes to the same all-girl high school as her; she is similarly well-known and experienced in modeling. Anna spends a lot of money on clothes, and enjoys modifying them to her own fashion style. She is first introduced in the first episode when she is with Maho at home, and the girls have decided to go out together. She briefly sees Shuichi, and coyly takes a picture before leaving. However, Maho and Anna unexpectedly return to retrieve Maho's cell phone, and come across Shuichi trying on and modeling Maho's dress outfit. Maho berates Shuichi for this, telling of the supposed " sickness " of such actions. Anna, too, at first disapproves of Shuichi dressing as a girl, and even calls Shuichi a " freak " soon after meeting Shuichi. Anna initially tells Maho she has no interest in her "weak" sibling because of Shuichi's feminine looks and behavior.
At another time, Shuichi and Yoshino come upon a public park where Anna is doing a photo shoot. Anna recognizes Shuichi, but misunderstands who Yoshino is, calling Yoshino a girl who is cross-dressed as a boy, and as such, supposedly Shuichi's girlfriend. However, Anna begins to take an interest in Shuichi when asked about complexion problems, since Shuichi has begun to develop acne. Later, they meet in a drug store, and Anna once again takes time to explain how to obtain and maintain a clear complexion.
Anna becomes more prominent in the anime when Shuichi takes an interest in her, and starts to date her, later both of them go out on a date in public while Shuichi is dressed up as the correct gender of that of a teenage girl. Later, she continues to date Shuichi for a period of time, until she breaks up with Shuichi, out of social fear and the inability to offer compassion to Shuichi. However, the two soon resume their relationship with each other after Anna does some serious heart-searching. Anna knows about Shuichi's tendency to dress as a cute, teenage girl, and eventually becomes supportive of it.
When Shuichi comes to school dressed as a teenage girl, wearing a sailor suit, and is bullied and expelled, Anna becomes emotionally distraught with grief, even to the point of crying her heart out, for what has happened to Shuichi. Even later, Shuichi states to Anna that being a teenage transgender person is just who they are. Furthermore, Anna's opinion of Shuichi presenting as female also changes, she eventually saying that it actually suits Shuichi's inane cuteness. She feels Shuichi is an interesting person, and once says Shuichi is like a 'cute little sister'. Anna, deep down, comes to know that being a transgender person is who Shuichi authentically is, and that Shuichi knows that it may be uncomfortable for Anna to acknowledge, but Anna must know that Shuichi's future may include becoming a young woman. With these revelations exchanged with each other, Anna confesses that Shuichi was the first person to get to know her as an intimate friend who consented to date her. Shuichi confesses to Anna that they have always loved her all this time, even after the their dating relationship was temporarily suspended. Even after this 'baring of their souls', just before the school's cultural festival play, Anna accepts Shuichi as their authentic self, and they agree to continue their dating relationship anew, implying that they will eventually marry and be together forever.