Nanako is one of Yamazaki's classmates. She is studying to become a voice actor.
Yamazaki has a crush on her. In fact, the heroine of the eroge he is working on is based on Nanako's appearance.Manga Spoiler:
As Yamazaki is about to leave Tokyo to inherit the farm, Nanako tells Yamazaki to break up even after Yamazaki's speech because she never actually liked him. Nanako tells Yamazaki that Yamazaki likes "pretty girls", and how she likes them too. She admits that she stalks girls ever since high school and how she only voice acts as shonen male characters in order to be the hero to cute girls and how she picked her hairstyle, as she believed it was something girls would like. She also admits that she only dated Yamazaki to prevent bad rumors.