I think the baseball is most popular sport in Japan and "KYOJIN" is very famous baseball team in Japan. When the high-school-baseball mach is hold, almost all Japanese watch the game and they always support the player. Many people are moved and become happy to watch the games. Actually, I had played softball for 7 years, so I really enjoy watcing the baseball game!
I think the most popular and famos artist is ARASHI in Japan. They sing J-POP songs and they are loved by many people. They are a idol group in Japan and they have a so many fun who are in elementary school or 70, 80 years old. I do not know about them so many, but I think they are funny and their songs are good to listen with friends.