Opinions vary..........according to this.........baseball IS Japan's most pop. sport...............South Korea i believe it is soccer............South Korea was the 1st country.........in all of Asia to have a pro soccer team......................i read that somewhere.....

Japanese baseball finds itself at a crossroads | Reuters

https://www.reuters.com/...baseball-japan/japanese-baseball-finds-itself-at-a-crossroads...

Aug 9, 2018 - TOKYO (Reuters) - Baseball could be losing its status as Japan's most popular sport as more and more children turn away from the game due ...