Nikkei press reported 2015 solar cell market share in Japan. According to it, the top supplier is Sharp (13%).
Figure: 2015 Solar Cell Market Share in Japan
|Manufacturer||Market share (%)|
|Yingli Green Energy||10.0|
|Hanwha Q CELLS||8.3|
Source is Nikkei Sangyo Shimbun newspaper, the article on 2016 July 25th.