Nikkei Press estimated the market share of courier service (door-to-door delivery) in Japan in 2015. According to it, Yamato has the biggest share (47%). Last year (2015) the courier services delivered 3.7 billion packages in total.
Figure: 2015 Courier Service Market Share in Japan
|Courier||Market share (%)|
Source is Nikkei Sangyo Shimbun newspaper, the article on 2016 July 25th.