One night and two days of 1 night and left alone by my wife's sister who suddenly came over

It's been two weeks since my wife became pregnant and went back to her hometown. Meanwhile, Tatsuya was enjoying living alone. However, the lonely life without anyone to talk to was gradually beginning to cast a shadow on Tatsuya's heart. At that moment, my wife's older sister, Kanone Kanon, came to check on her. Tatsuya is surprised by the sudden visit but is pleased. Kanon welcomes her with a great welcome, but her true purpose when Kanon appears was to resolve her daily frustration with Tatsuya...