The research area of human robot interaction has started around 2000and we have studied it more than 10 years. The conference is glowing, but on theother hand we are feeling the limitation. One of the reasons is the concept of interaction is too broad. We need to focus on the key issue. The author believes it is mutual leaning between humans and robots. Mutual learning is the most important purpose in the human society. We will be a member of the society for learning something from others. This paper discusses on human robot learning for deeply studying the human robot interaction and realizes robots that work in our future society.