Mitsuki, the daughter of a remarried parent, is a serious, cute, and popular sister-in-law who is proud of everyone.I was living a happy life with such a sister.One day, her parents left for a day trip in the morning.I decided to spend the day alone with [Mitsuki].She was leading a normal life, but when she was alone in the living room, Mitsuki, who was always cute, changed her behavior.She kissed me covered in saliva, showed off her masturbation, came to wash my body in the bath, and became super aggressive and came to steal my body...What should I do!