Hokkaido, Japan is Winter Wonderland of the East

Hokkaido (北海道, Hokkaidō) is the second largest, northernmost and least developed of Japan's four main islands. Its weather is harsh in winter with lots of snowfall, below zero temperatures and frozen seas, while in summer it does not get as hot and humid as in the other parts of the country.

With its unspoiled nature, Hokkaido attracts many outdoor lovers, including skiers and snowboarders in the colder seasons and hikers, cyclists and campers from June to September.

Despite being Japan's second largest island Hokkaido remains its least populated region and it retains a distinct frontier feel, partly explained by the fact that it has only relatively recently come under true Japanese control. Both in climate and culture this stunning island represents a refreshingly different side to Japan, unique among the country's many jewels.

Most of Hokkaido was settled by the Japanese within the last 100 years, compared to the thousands of years of Japanese history and pre-history. Before that it was only inhabited by the hunter-gatherer Ainu culture. As a result, its architecture and cities are much more modern, and mostly based on western-like grid layouts.

How to get to Hokkaido (source: Wikitravel)

By plane

Sapporo's Chitose Airport is Hokkaido's sole international gateway of significance, with flights to Hong Kong, Taipei, Kaohsiung, Shanghai, Beijing, Seoul and Busan. However, there are only limited international flights and most visitors will need to transit through hubs such as Tokyo and Osaka. The route between Tokyo and Sapporo is, in terms of capacity and planes flown daily, the busiest in the world. (Note that Narita Airport and Haneda Airport are quite far apart from each other, so make sure you factor in at least 3 hours travelling time between airports in Tokyo.)
In addition, there are a few international flights (mostly from Seoul and Taipei) to both Asahikawa and Hakodate.

By train

Hokkaido is not (yet) linked to the Shinkansen high speed network, but night sleeper trains from Tokyo are a popular option.
Another way to access Hokkaido by rail is the Hakucho and Super Hakucho limited express service between Aomori and Hakodate (2 hours, unreserved seat, ¥4,970 one way). There are nine trains per day.
When the Seishun 18 Ticket is effective, it can be used on Hakucho limited express trains between Kanita and Kikonai, making it possible to cross between Honshu and Hokkaido for as little as ¥2,000. However, because of the scarcity of local trains around Aomori and Hakodate, scheduling such a trip can be a bit of a hassle.

By ferry

Ferries are mostly popular among people bringing their own cars to Hokkaido.
Ferries from Hakodate link to northern ports in Tohoku, including Aomori and the Shimokita Peninsula.
Otaru provides links to Maizuru (near Kyoto) and Seoul.
Tomakomai connects with Akita, Niigata, Tsuruga, and sometimes Maizuru.
Wakkanai has ferries to Russia.