Revenge For The King Of The Household: When I Gave My Sister, Who Was Always Superior To Me, A Sex Drive Enhancer Concentrated 100 Times As Revenge, She Fell Into A Frenzy And Got A Boner Even Though She Was My Little Brother. Rei Kamiki

I hate my older sister. After my father was laid off, my sister's income became our family's lifeline. From that point on, my sister became the king of our household, and the rest of the family turned into her servants. I took a dangerous aphrodisiac that a friend had left with me, concentrated it 100 times, and administered it to my sister half as revenge and half as a joke. She ended up completely zonked out and turned into a pathetic slut. Even as her little brother, I got hard.