In this story, we follow two siblings - an older brother named Tsuki and his younger sister Uta. They live together due to their parents being absent or deceased. Tsuki has become consumed by alcohol and gambling, while he subjects Uta to daily sexual abuse. Uta endures her life out of necessity, trying to survive under these harsh conditions. One day, Tsuki decides that since she's grown up now, he wants her to sell herself for money. He starts by forcing himself onto her. Once he realizes how much profit they can make from this arrangement, he begins inviting clients over for nonstop creampies and anal penetration.