Imouto wa Kanojo ni Dekinai no ni

A junior high student with a cute and charming personality, she is often seen as the ideal little sister. Despite her young age, she has an attractive appearance and frequently behaves in affectionate, sometimes teasing ways toward her older brother. At home, she maintains a childish demeanor, and their relationship has always been perceived as purely familial. However, this changes when it is discovered that they are not biologically related. This revelation alters the nature of their relationship, making it possible for them to be more than just siblings.