Studying Japanese as a foreign language requires the learner's skills and abilities to understand grammar and master the four language skills so that the learning process will be maximized. Therefore, appropriate learning methods are needed to answer these outputs. The focus of this research is the application of the case based teaching method to improve Japanese language skills. The population in this study was the second semester students of the Japanese Language Education Study Program at a private university in Jakarta, total 39 respondents, each in class 2A with 20 respondents as the Experimental Group with the case based teaching method, and 19 respondents in 2B as the Control Group. Using traditional learning methods. Case-based teaching methods are giving cases, identifying key cases, exploring case values, conducting analysis and argumentation, finding solutions to identified problems. The instruments that will be used in this research are tests, questionnaires, observations, and interviews. It was found that applying the casebased teaching method provides innovation and new creativity in the teaching and learning process, as well as an increase in students' four language skills, namely the ability to listen, speak, read, and write. It can be concluded that the case based teaching method has an effect on increasing student's Japanese language skills. Of the many concepts about the case based teaching method, not many have applied it in Japanese language learning which can produce higher-order thinking skills with collaboration, so this research is something new.