On her way home from club activities, Rin takes a nap in the living room in her uniform. Her unprotected appearance, her older brother who was lustful to her panchira started masturbating while sniffing her sister's gym clothes. Sister who wakes up and pulls. But she can't hate her brother, so she's going to be uncomfortable if she stays like this, and her sister suggests that she help him masturbate. However, my older brother is not cool. A younger sister who also responds to her older brother's request to change into her gym clothes. But it's not cool. "Onii-chan, we're brother and sister, so we can't insert it, but if it's just costume, it's fine. Don't let it out."
