yuki (character), ri ei ko bouryaku no rensaieko, rieko (character), game cg, 1boy, 1girl, age difference, arms at sides, blush, brother and sister, brown eyes, censored, closed eyes, curtains, dutch angle, hand on another's head, handjob, hetero, incest, indoors, long hair, mosaic censoring, naughty face, nose blush, onee-shota, penis, penis grab, purple hair, school uniform, short hair, shota, siblings, standing, teenage girl and younger boy, testicles