Machi is the youngest of three siblings. The siblings live happily under the same roof, but they have a secret that they can never tell anyone. The sadistic eldest brother devours his sister's body almost every day, while the masochistic second brother gets an erection just from seeing Machi like that... One day Machi is made to cum by her eldest brother's huge dick, and another day she seduces the second brother and plays with his dick. This is the daily record of the three lewd siblings, for whom incest is a natural part of their daily lives...