"No words are needed for my physical relationship with my sister." One day, my parents remarried... and Ichika, the step-sister, came to our house. Suddenly, I was living with a cute sister who wasn't even related to me by blood. I couldn't help but be conscious of naughty things. One day, while my parents were out, I was alone with my sister... I was even more conscious of her than usual, and when I looked over, I noticed that she was also conscious of her... and without any conversation, we silently did it, just by the atmosphere. That was the beginning of our physical relationship, where "when our eyes met, we would silently do it like monkeys"...