GVG-578 Real sex education of older sister Hibiki Otsuki

Hibiki lives with his younger brother and father. Hibiki, a younger brother, warned his father, an AV enthusiast, "What if my younger brother sees it!" However, one day, my younger brother mistakenly sees his father's AV. A younger brother who misunderstands SEX as a scary thing and cries when he hears it. In order to correct such a younger brother's sexual knowledge, Hibiki used his own body to teach about true SEX.