Bom Do, a timid middle school student, is unable to refuse anyone due to her fear of being disliked. Her sole confidant is her grandmother, an extroverted woman who raised her and her sister. One day, following an accident, Bom's grandmother awakens in her granddaughter's body. Can the grandmother, who is the polar opposite of her granddaughter, adapt to school life while searching for a way to return to her own body?