Google is the most used search engine in Japan.

Japan’s search engine market share is below.

PC：

Google　72.3％
Bing　16.8％
Yahoo！　9.86％
source:
https://gs.statcounter.com/search-engine-market-share/desktop/japan/

 

Mobile：

Google：80.7％
Yahoo!：17.5%
source:
https://gs.statcounter.com/search-engine-market-share/mobile/japan

 

However, AI is gaining momentum in Japan and this share may change in the future.