School life tidbit: I am invited to class

Formality and politeness are important aspects of Japanese society and education. Students have to announce their presence before entering the staff room. In some schools they are not allowed to enter the staff room unless a teacher acknowledges them. Students also have to announce when they leave the staff room. As part of this culture of politeness I am offered an invitation to each class I go to. Students will come to the teacher before their class in order to help them carry any of the day's materials. If I am to be a part of the class that day, the teacher ushers the students over to me. The first years still look to their teacher for guidance, but the older students have mastered the English. "Caitlin, please join us for 3B." It is usually the boy who speaks as the girl demurs to him. I always respond, "Yes, I will. Thank you. See you!" It's a strange thing to be invited into a classroom every time. In part it is stand-offish as if I am still a guest who doesn't know where to go. On the other hand, it forces the students to speak English and be the active player in the conversation instead of passively responding to my questions.