A useless little brother who doesn't work, spends all his time playing pachinko, has been disowned by his parents, and is staying with his older sister and her husband with nowhere to go. His older sister, Iori, can't scold her little brother and spoils him. Eventually, a loan shark comes to their house. Witnessing this situation, Iori pities her little brother so much that she tells the loan shark that she will take his place. The vile loan shark enjoys humiliating her righteous sister in front of her brother. Unable to refuse, the sister becomes the loan shark's masturbator and falls prey to his raw dick.