Nikkei press reported 2015 wind power output market share in Japan. According to it, the top supplier is Eurus Energy (21%).
Figure: 2015 Wind Power Output Market Share in Japan
|Manufacturer||Market share (%)|
|Japan Wind Development||6.1|
|Clean Energy Factroy||2.7|
Source is Nikkei Sangyo Shimbun newspaper, the article on 2016 July 25th.