Russia to Japan
 

There is a ferry route from Korsakov on Sakhalin island to Wakkani in Hokkaido, Japan. I haven't ridden it myself, but I was curious so I asked the ferry company (Higashi Nihonkai Ferry) about rates. 30,000yen (about $275) per person plus 8,000yen ($75) for a motorcycle.
Runs about 3 times a week in the summer. Schedule is available at http://www.kaiferry.co.jp/saharin/goto/Schedule.html
It is in Japanese but you may be able to figure out the dates. Left side is from Japan. Right side is to Japan.

Dan Walsh was worried about the lack of transport from Siberia to Alaska. You may be able to find something in Japan. But directly to Alaska may be expensive. (I say this without experience, may be wrong)

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