Big Sister's Real-Life Elastic Education: Nanase Otoha GVG-333

Although Nanase Otoba lives happily with her family, she doesn't have a boyfriend yet. One day, a friend talks to her about how great it is to have sex with your boyfriend, which makes her want to try it too. At the same time, even her younger brother has a girlfriend. So, under the guise of sex education, she uses her younger brother as a practice subject for sex...