Shindou Rei
from Boku wa Ohimesama ni Narenai
The token Cinderella of fairy tales, she is mistaken for a boy by many characters since she comes from a poor family and can only afford to wear hand-me-downs from her brother. When she does manage to wear girly clothing, she identifies herself as Rei's cousin "Reira" to hide her identity out of embarrassment.

Boku wa Ohimesama ni Narenai
Shindou Rei (Cinderella) comes from a very poor family. Her only clothes are hand-me-downs from her brother, even her school uniform. So everyone always mistakes her for a boy. Even her close friend Hakuba Ouji (white horse prince), who starts developing confusing feelings toward her all the while believing she's a boy. Tsukumo Yuki (Snow White) is the leader of a delinquent gang and falls in love with Rei at first sight, also believing her to be a boy.