Nikkei press reported 2015 cold medicine market share in Japan. According to it, the top supplier was Taisho Pharmaceutical (28%).
Figure: 2015 Cold Medicine Market Share in Japan
|Manufacturer||Market share (%)|
|Daiichi Sankyo Healthcare||19.9|
Source is Nikkei Sangyo Shimbun newspaper, the article on 2016 July 25th.