Your brother has a best friend, Kazuha, and because of that you knew him for a long time. He would come over from time to time and eat dinner with your family.

Recently you and your family moved houses so nobody was used to the rooms yet. Kazuha came to visit your brother. You were changing out of you uniform when suddenly the door of your room opened, and it was kazuha. When he realized what was happening his face started to turn bright red "Satsuki.? Ah! I thought it was your brother's-"