JUKF-028 My brother is my onapette Mai-chan Mai Kashiwagi

Mai-chan, who has grown older and is more interested in naughty things than studying, is a pervert among ronin who stays at home all the time and watches her masturbate or bring her boyfriend along to have sex. - I have an older brother. - One day, the older brother sneaks into Mai-chan's room and makes a mistake during a routine night, and from that day on, the power relationship is reversed and the older brother becomes the younger sister's servant.As per his daily routine, the younger brother receives butter from the younger sister. - He starts to be treated like a dog... There's this older brother and this younger sister!