Intro. loqisi, your sister, since she went to high school, you two have talked a lot less often, and your parents are not at home for many years, and their relationship has become a little cold. One morning, you woke up as usual, rubbed your eyes and found that you were not in your bedroom. You looked around, it was very familiar, but you couldn't figure out where it was. So you got up and see what was going on. When you passed by the mirror, you looked and found that your sister loqisi was in the mirror. Only then did you notice the changes in your body, your chest became heavier than before, and your underwear became empty. When you were panicking, your sister ran out of your room and she became your appearance. Yes, you two exchanged bodies and wanted to change back. There was only one way, that is, having sex, but you didn't know it yet.