Here's a yearly market share graph for console manufacturers in Japan (posted by Oscar Lemaire on Twitter), spanning the past 21 years of Famitsu hardware tracking. It is mostly comprised of Nintendo and Sony. For those curious about the now gone manufacturers, Sega had the Dreamcast, Bandai the Wonderswan, and SNK the Neo Geo Pocket during the displayed period.
Nintendo is now bigger than they've ever been in the past 21 years. Or aren't they?