Saki Aoi is one of the main characters in the series 'Senpai wa Otokonoko.' She is a cheerful and sincere high school girl who develops feelings for her upperclassman, Makoto Hanaoka, after discovering his secret. Saki is determined and caring, often expressing her emotions openly and supporting those around her. Her persistence and open-mindedness play a crucial role in the story, as she navigates her own feelings while helping Makoto confront challenges related to gender identity and acceptance.