Daisuke has been living a lazy life ever since his wife went back to her hometown to give birth. Then suddenly, his wife's sister Chiho comes to help with the housework. Daisuke, who is fed up with his messy room, welcomes Chiho, but... Daisuke can't help but get excited when he sees Chiho's panties and her voluptuous thighs every time he cleans. Chiho smiles at him with a cute smile and clings to him, and his last bit of reason disappears...