The process of improving teaching plans using cartoon-based teaching simulation, and the effects of the improvement process were examined. When expressing a teaching plan using cartoons, conversations and actions between the imaginary teacher and learner in a realistic classroom setting are materialized. However, the burden of the activity was high for student teachers lacking teaching experience. When reviewing the cartoon, the student teachers noticed issues that were not previously considered. They would also try to look from the learner's viewpoint. The student teachers were also more conscious of the purpose of the class, and tried to grasp the essence of the class. From this research, it has become relevant that in order for student teachers to improve the teaching plan by themselves, in addition to the cartoon-based teaching simulation, reviewing the simulation is also inevitable.