Maya and Yu, a good-looking couple who envy the surroundings. The two have recently started living together and have fostered deep love. One day … Yu’s younger sister, Kokoa, came to Tokyo from her parents’ house. Yuu is pleased with the reunion after a long absence, and Maya cannot hide the joy of seeing Yuu’s sister for the first time. However, Shina had a certain spirit. “You want to take away people’s things.” Shina steadily begins preparing to take her sister’s lover, Maya, to sleep. And the day of decisive action will come …