Ane de Shikoru Otouto to Onaritai Ane ga Souguu shita Kekka

This is an incest story between an older sister and her younger brother. The younger brother is the top, and he relies on the momentum of the situation to do the deed. The older sister is stoic and her emotions don't show on her face. However, her true face is that of a perverted girl who leaves school early because she wants to schlick. One day, the older sister left school early and came home to see her younger brother fapping in her room... what's more, he was using her picture as fap material. What will his horny older sister do upon seeing that? (Source: DLsite)