Much like Chile, there are a range of different climates in Japan. The North (Hokkaido to Nagano) is extremely cold in winter, while the winter in Okinawa, the most Southern Islands and Kyushu, can be called agreeable to acceptable. This diversity gives the country a lot of options when it comes to practicing sports. I'll focus in this article on four board-sports. Snowboarding, skateboarding, surfing, and windsurfing.
Snowboarding
Since the Olympic winter games in Nagano 1998, the Japanese have developed a fondness for winter sports. From ice-skating to skiing, every sport practiced in the snow or on ice has gained popularity. Initially there were only a lot of skiing places around Nagano, but the rising popularity of skiing has led to the birth of a lot of skiing areas with good facilities. While Nagano is still popular, a lot of Japanese choose for Hokkaido now. Being more Northern than Nagano, there are areas with guaranteed snow and the facilities are growing to an agreeable level. With all this attention to skiing, it is easy for snow-boarders to use the facilities too. Being not as popular as skiing, there should be no trouble for you to find your snowboard gear in any skiing area. Even the après-ski is bound to be as fun as it would be in one of the expensive ski-resorts in the Alpes. So Japan is good to go.
Skateboarding
While skateboarding can be done in Japan and is regarded as cool amongst the youth, there are some obstacles to overcome. Skate-parks are rare and only located in the big cities. Most of them are indoor skate-parks and since there is little choice, you can grow bored and you get no alternative to choose from. As for boarding outside, it can be hard to find places suited for boarding. Almost in every town the police won't be happy with your performance. So good luck with finding a private place that's good for skateboarding. There are some places in the big cities, where you can hang out with fellow skaters, but they are rare and not easily discovered. The same goes for finding gear. You can find some skate-shops, but they will not be cheap and only a few can get you everything you want. I think if you have some skateboarding Japanese friends, you're good to go, but just going there by yourself you'll be completely lost.
Wave Surfing
Geographically Japan is interesting for wave surfing. The reefs near Okinawa and the weird cracks under the sea near Kyushu can bring you some weird waves. In Okinawa all year through and in Kyushu in summer, surfing gains popularity. It's considered as one of the cool sports and more places where you can buy or rent equipment are starting up. Most of the equipment is imported from Australia and the quality is pretty high. Since surfing in Japan is still in growth status, you can find untouched havens and so on. I would really recommend Japan for the experienced surfer. If you are not yet very experienced, you may want to try some more touristic places in Okinawa. Or you can always try to find a Japanese friend who likes to surf and knows a certain area pretty well. Like I said Japan has some weird waves and you better be careful before throwing yourself into the water.
Wind Surfing
Japan has a lot of sea and quite enough wind. For the conditions for windsurfing you will never have to look far. But climate-wise and equipment-wise you are better off South in Kyushu or Okinawa. Wind surfing is not extremely popular in Japan. It doesn't mean that you can't find it anywhere but you will have to inquire first. Either there is a club and you'll find everything or people will stare at you like you've asked them whether the synchronized swimming team practices in this part of the sea. In some places they will even have a synchronized swimming team, but no windsurfing. So in short: you will not have to complain about circumstances, but more about material or finding a club.
