The story primarily centers around the daily life and adventures of the main characters, often delving into comedic situations, emotional moments, and the exploration of sibling relationships. While specific plot points may vary, the anime generally maintains a light-hearted and heartwarming tone, making it relatable and entertaining for audiences.
However, things take a surprising turn when Shiori discovers that Onii and Kano have broken up, and Onii starts developing feelings for Shiori. As the series progresses, Shiori and Onii grow closer, but their relationship is put to the test as they navigate their feelings for each other. aneki... my sweet elder sister the animation