She survives on the money her older sister earns from sex. (Airi Hishima, SAME-056)

After our parents disappeared, my sister and I depended on each other for survival. My sister worked as a temporary worker, barely making ends meet on a meager income, and still couldn't escape poverty. I thought my sister was as beautiful and charming as our mother, and in no way inferior to her without exaggeration. If we could make better use of our strengths, we could live a wealthy life. However, she always complained about not having money. Therefore, I decided to use my sister to make money.