Super caring older sister solves all her younger brother's problems with his penis. (Natsume Hibiki STARS-469)

"I want to wash my brother's foreskin... I want to test how far the foreskin can reach on my brother's penis... I want to measure the size of my brother's penis." "I want to strengthen my brother's premature ejaculation penis... I want to insert my brother's virgin penis." The wishes of Natsume Hibiki, a very nosy older sister (a college graduate/working office lady), (to do what she wants). All of this needs to be done. By the way, my brother is a shut-in.