Oosachi Nao

The kind, flawless younger sister who loves her older sister Asuka a lot, devoting everything of herself to support her. The self-proclaimed "Responsible Imouto", "Onee-chan's Special Medicine." While they're born one year apart and in the same grade level, Nao has cared about Asuka (who's not good at studying) to the point where she helped her sis get accepted into the Imperial Capital Nursing Technical School, even enrolling herself to the very same school just to be with Asuka.