[Muraimura] My Sister Is A Closet Pervert!! [tsuyoshi]

A younger brother is caught off guard when his big sister reveals her hidden perverted side, leading to an intimate encounter in a bathroom and later in school uniforms. The sister’s confident, teasing demeanor turns the sibling rivalry into a charged incestuous tryst, while the brother struggles with surprise and desire. The narrative mixes comedic shock with erotic tension, highlighting the sister’s dual nature as both innocent student and daring pervert.