At its core, Aneki: My Sweet Elder Sister is a character-driven anime that focuses on the intricate relationships within a family. The series centers around Akira, a 14-year-old junior high school student, and her elder sister Aki, who is 18 years old. After their parents' divorce, Akira's father remarries, and Aki returns to live with the family. This reunion sparks a chain of events that forces both sisters to confront their feelings, insecurities, and expectations.