The best selling mirrorless camera in Japan for 2012 according to BCNranking is the Nikon 1 J1. The data is based on actual sales from approximately 2/3 of all Japanese retail stores.
In the DSLR ranking, Canon has the #1 spot followed by the Nikon D5100 and D3100. The D7000 got the number 5 spot with a total of three Nikon DSLRs in the top 5 list. Nikon D3200 is at #11, D800 at #16 and Nikon D600 at #20:
