actually soccer is big in Japan, the national soccer team is extremely popular, and many people follow the Japanese players in the european leagues. Over the last 20 years the popularity has grown so much in Japan it's pretty amazing, same thing has happened in other countries such as Finland.
I was also part of the soccer club at the university there, the only thing more popular than that was the baseball club.
Let me give you an example of how big the national team is in Japan, during the World Cup last year i was in Japan and I was watching the game at my place with some friends. My girlfriend (at the time) had to go home and I walked to her to the station, which normally you'd see about 50 people on your way there. As i walked down the street to the station i passed a bar which everyone in it was glued to the TV screen watching the game, passed a yakitori shop and again everyone in the shop was watching the game. I didn't even see 1 person outside on the way to, the way back, or inside the station (besides workers). It was so bizarre, it was the only time i'd ever seen the street empty in 11 months that i lived there.
currently playing: Skyward Sword, Mario Sunshine, Xenoblade Chronicles X
