This paper is a part of the study on the start of the Japanese class, which analyzed how the opening section is transferred to the main section by the interaction of the participants (students and teachers) from a multimodal viewpoint. The purpose of the research is to clarify the mechanism of class conversation, and to find clues for class participants (especially new teachers) to participate in classroom activities. The transition from the opening section to the main section is mainly composed of three procedures: ① Teacher's preparation of instructions, ② Teacher's instructions to enter the main section,③ Students's reaction to the teacher's instructions. The 2nd and 3rd procedures were observed in all classes, however the 1st procedure just appeared in a few classes. Through those procedures by verbal behaviors and non-verbal behaviors, participants completed the transition.