Just recently found out Princess does not pay for your Visa, so obtaining Visa for China and Russia will cost aproximately $450 USD (assuming you're US citizen). Japan does not require US citizen to have Visa to enter Japan.
for additional questions about obtaining Visa:
Sam's Passport and Visa Services Contact Information
Please note you do not need to obtain entry Visa for Russia/Korea (Princess cancelled Japan and added Korea as new port of call)
btw, I am perturbed by the fact that American jobs are shifting to China and the Americans are pouring their money to help build China economy (new airport, bigger highways...etc) and the Chinese government is charging Americans expensive Visa to enter the country? unbelievable.....