My older brother Nanami always teases me for being unpopular with girls. But deep down, she truly cares about me—and to prevent my daily nocturnal emissions, she uses knowledge from adult manga to help me release my sperm. This meddlesome sister not only flaunts her naughty side but also acts in a way that's oddly funny and adorable. Going far beyond her role as my sister, she seems like a genius when it comes to sex. I know this kind of behavior is wrong, but I can't resist her cuteness. I'm completely overwhelmed by Nanami's charm, where her kindness and eroticism blend perfectly together.