Traditional Japanese medicine, Kampo, is used by over 80% of medical doctors in Japan. Owing to its high quality and safety, Kampo has been integrated into modern medicine, and there are 345 randomized controlled trials using Kampo in Japan as of 2010. Although there are a number of articles in top journals about basic science research, we can find only small numbers of high-quality clinical evidence. Since undergraduate education on Kampo has been established, integrative approach with the balanced combination of modern medicine and Kampo is expected to generate good clinical evidence in the near future.