Because I Don't Like My Big Brother At-All--!!

Nao Takanashi, a second-year middle schooler, adores her older brother Shuusuke so much that she's developed a "brother complex." Determined to make him see her as more than just a little sister, she constantly flirts with him-and Shuusuke, though exasperated, often plays along, encouraging her antics. One day, while cleaning out Shuusuke’s room and tossing his porn magazines, Nao stumbles upon an old photo album filled with his childhood pictures-none of which feature her. After learning the truth about their family ties, she grows even more clingy toward him. But her hopes of having Shuusuke all to herself soon face an unexpected challenge.