An obedient and cute growing girl, Rena-chan, has an older brother who is a doskebe ronin who is lurking at home all the time and peeking at the place where he is masturbating and where he is having sex with his boyfriend. One day, her brother sneaked into Rena-chan's room and tried to crawl at night, but it was found out, and from that day on, she became her sister's servant and was forced to cunnilingus like a butter dog from her sister like a daily routine. It seems that there is ... this brother and this sister!
