I think baseball is the most popular sport in Japan. Because people can always get excited because many people have been playing for a long time and now there are amazing people like Shohei Ohtani who can change the history of baseball.
Nowadays, K-pop is very popular in Japan. I have been listening to K-pop since I was a little kid and until about 7 years ago I was very much in the minority. However, since the group BTS went international, K-pop has become known to many people. I have a lot of respect for BTS. I hope that Japan will have artists who can spread J-pop to the world.