Two weeks have passed since his wife became pregnant and returned to her hometown. Tatsuya has been enjoying living alone during that time. However, the lonely life with no one to talk to has begun to cast a shadow over Tatsuya's Kokoro. At that time, his wife's older sister, Kanon (Kanone), comes to check on him. Tatsuya is surprised by her sudden visit but happy. He welcomes Kanon with open arms, but her real reason for appearing is to relieve her daily frustrations with Tatsuya...