MIMK-113 Dealing with my little brother's sexual urges is something that a sister should do, according to big sis.

【The sexual common sense of my stepsister, born from my father's remarriage, has collapsed！！】Based on the original work 'Extreme Service Big Sister' by Seiji! Morning, after school, before dinner, after dinner... At school, in the living room, on the stairs, in the bathroom... In ＜any situation＞, big sister rushes to take care of her sexual desires! Whether you want it or not, if she finds someone with sexual desire, she'll immediately take care of it! Welcome to the babymaker swamp of a short-statured, big-breasted sister who accepts anything!