While his wife was pregnant and visiting her hometown, Yuta was busy with the housework. Having lived alone for a long time, he didn't mind doing the housework and cooking, but it was still lonely. Just when he was feeling lonely, his wife's sister Rin came to check on him. Yuta was happy to welcome Rin back to the house, as it had been a long time since the house had been lively, but... Rin's real purpose was to relieve her sexual frustration with Yuta...