Our cruise was actually three 9day cruises and took us around Taiwan, to S. Korea, an island off Russia and all of the main Japanese islands.
Princess has now fitted the Diamond Princess to attract Japanese cruisers. They have installed the Japanese bath (very nice but not used by most other cultures). Meal time is fixed but the buffet has a wonderful variety for those who opt out of the fixed dining hours. We found many of the dining room options were on the buffet at night.
As usual,all crew and staff were wonderful.
We are elite so we get free laundry but I would not recommend sending anything you are not willing to have ruined. I had two tops that came back with huge stains and basically got no satisfaction.
We cancelled most of our a Princess excursions once we realized that there were free shuttles to town at most ports and some of the excursion sights were close by. This was the first season so the Japanese port cities are very anxious to please the passengers. Many of them had lots of booths at the ports and most of them had entertainment at the ports as we left the ports. On several occasions, we saw entertainment that was equal to what we had paid to see ashore.
I have always wanted to travel in Japan to see the ancient temples and shrines. We found out that basically they all pretty much look the same and most are current reconstructions due to fires, war, and earthquakes.
Pictures on walls are copies while the originals are in museums.
We loved the Japanese people and found them to be very considerate and polite.
Japan can be pricey but we were introduced early to the Daiso (100 yen) stores. Many of the larger port towns have them.
On the ship, the boutiques are now high end and cater to the Japanese. Forget it if you are a large American and you like to purchase port T-shirts. Their size Xl is for Orientals and is like a size Med.
Basically, we enjoyed this cruise but would not pay the airfare or spend the time to fly to Japan to do it again.