My cute but strict sister found the test I had hidden and was furious. After studying hard, I got 100 points... so I asked her to be my maid. I put everything into these three days alone with my sister. She obeys her master's orders, but her true self comes out and she obeys my orders even though she frowns when I do something erotic. It feels so good that she gradually becomes obedient in this tsundere Minami Hatsukawa!!