For the innocent and cute girl in development, rena-chan, there is an older brother who has been lurking at home, masturbating or peeping at her having sex with her boyfriend. One day, the brother tried to sneak into rena-chan's room for a night attack but got caught. Since then, he has become his sister's slave and is forced to perform cunnilingus like a butter dog every day... This brother and this sister are truly made for each other!
