Nikkei Press estimated the market share of home-use game soft in Japan in 2015. The total sales were 34 million packages in 2015. According to it, Nintendo has the biggest share (25%).
Figure: 2015 Home-use Game Soft Market Share in Japan
|Manufacturer||Market share (%)|
Source is Nikkei Sangyo Shimbun newspaper, the article on 2016 July 25th.