BCN+R published their latest sales results data for the mirrorless camera holiday shopping season in Japan. What I find interesting is that Canon and Nikon mirrorless sales were almost identical in December of 2018:
We already knew that Sony dropped to 67% back in November of last year when Nikon and Canon announced their full-frame mirrorless cameras:
BCN Ranking full-frame mirrorless camera market share: Sony: 67%, Canon: 22.1%, Nikon: 10.4%
My guess is that Sony sales will drop even further after Panasonic joins the full-frame mirrorless market in March with their S1/S1R cameras.
FYI: BCN+R collects sales data from approximately 2/3 of all Japanese retail stores.