My cute little sister is usually very serious, but she's busy with her club activities and part-time job and doesn't seem to have time to find a boyfriend. After coming home and changing from her uniform into loungewear, she seems to be searching for something on her smartphone. She unfamiliarly rubs her budding breasts and fiddles with her crotch through her clothes. Then she seems to get excited, as she exposes her bare legs, opens them, and masturbates enthusiastically, moaning sweetly. She awkwardly fiddles with her pussy, and then uses a vibrator given to her by a female friend to bring her to a convulsive climax. My sister's masturbation is too defenseless.