GVG-445 Big Sister's Real Sex-Ed Yuna Himekawa

Recently, my younger brother started to look at my father's erotic books and peek at my mother's masturbation. Her older sister Yuna, who couldn't stand it, warned her younger brother, but instead sympathized with her wrong sexual knowledge. Her brother, who seems to ask anyone about her masturbation and sex, shyly spreads her own genitals and starts sex education.