Watashi ga Oneechan Nan Dakara ne!

Fifteen-year-old Misora Takatsuki has just started her first year of high school, but she faces a daily struggle that has nothing to do with academics. Standing at an unusually short stature, she is constantly mistaken for an elementary school student. While her friends find her petite appearance endearing and frequently tease her about it, the lighthearted jokes only deepen her self-consciousness. For Misora, being treated like a child is a source of constant frustration, especially as she tries to navigate her new life as a high schooler. Her insecurities are further amplified by a stark contrast within her own home. Her younger sister, Kotori, is only eleven years old yet already possesses the mature appearance of a high school student or even someone older. This dramatic physical difference creates an awkward visual dynamic between the two siblings. Kotori adores her older sister and simply wants to spend time playing together, but Misora finds these innocent requests deeply embarrassing. As the elder sibling, she feels a strong desire to maintain her role, yet their reversed appearances make every interaction feel like a challenge to her authority. Caught between her sister's affection and her own pride, Misora must figure out how to embrace her position as the big sister despite looking like the little one.