JUKF-055 My brother is my wank pet, Natsu-chan of Natsuo

As Natchan grew older, she became more interested in sex than studying. She was always cooped up at home, either masturbating or bringing her boyfriend back to have sex, all while being spied on by her delinquent brother. One day, her brother sneaked into Natchan's room and failed in his daily night● activities. From that day forward, the power dynamics reversed, and the brother became a slave to his sister, being treated like a butter dog as part of his daily routine... You can't escape your bloodline; this brother and this sister are truly a pair!