Japan led the world in technical research and development into wave power converters until about 2000. Many people believe that wave energy can be utilized and that there are large amount of wave energy around the Japanese islands. This paper describes the development of wave energy converters in Japan. At first, it promotes the understanding of the wave power potential in Japan compared to the world, in particular the UK’s wave conditions. After that, it introduces different types of wave energy converters and details of each one. The purpose of the paper is to recognize the situation regarding wave energy utilization and exactly explain related matters. In Japan, although there is not plenty of wave power for electrical generation, there are several research projects on wave energy converters and development has progressed since the Fukushima accident in 2011. Very high performance devices under research. It is expected that wave power generation will be put to practical use in the near future.