The “Joint Research of Lesson studies between five universities and schools” in Japan had contributed to develop the concept of “Lessons” and movement of Lesson Study in Japan. There were major five universities which led Lesson Studies from 1962 to 1985. And those five universities developed each unique methodology of analysis and interpretation of lessons through the collaborative researches with each partnered schools. In this study the concept of “Lessons” is clarified, which have been developed through post-war movement of Lesson Studies in Japan as Joint Research between universities and schools, focusing on the methodologies of analysis and interpretation of the lessons. And we suggest a new methodology using a case study of Lesson study which aims at integrating the six perspectives, “Teaching Material-Oriented Approach”, “Child-Centered Approach”, “Group Formation based Approach”, “Objective-Based Approach”, “Method-Focused Approach”, “An Approach Based on the Way of Life”, for the lesson planning.