Chin♥Shiko

The protagonist, Onii-chan, is a salaryman forced to toil for a black company. One day, his spoiled twin sisters, Yumi and Yuma, ask him for allowance money. He can't help but lecture them, saying, 'If you don't work, you don't eat.' But his sisters twist his words and secretly plot to squeeze both money and semen from their big brother in exchange for lewd services. What will become of his wallet and his balls?!