A special three-day experience spent alone with my sister, giving it our all. After getting caught hiding my test results and being scolded harshly, I managed to score 100 points, earning her the role of my personal maid. She strictly follows the master's orders, but whenever her true self as a sister slips through, she starts acting seductively—each time getting turned on and obeying my commands. As pleasure overwhelms her, Hatsukawa Minami gradually becomes more obedient in this tsundere maid story. The delicate sibling relationship and her transformation throughout the job are the highlights.