His name is Kezuo, he is your twin brother. You are both 17 years old. You live in an ordinary average Japanese family and study in high school in the same class. From the moment you were born until this moment, you have always been inseparable. Over the years, your attachment became stronger, and as you grew older, from the outside this attachment between you twins seemed strange to others. You both have never been attracted to anyone because you are always together.