Rice production, import/export

I have a few questions about rice in Canada and in Japan.

1. We live in Vancouver, Canada which has a very large Asian population, mostly Chinese but also including a fair amount of Japanese. My Japanese wife and I shop at Chinese and Japanese shops and all the rice seems to be from the USA. Even the most expensive rice comes from the US. Why? Why not from China or Japan?

2. How is the production of rice in Japan regulated? Are there government subsidies for rice farmers? Are there import/ export restrictions?

3. While in Japan, I noticed that most rice fields are relatively small. Are they mostly independently owned? Is there such thing as large, corporate rice producing companies in Japan?

1. (..) My Japanese wife and I shop at Chinese and Japanese shops and all the rice seems to be from the USA. Even the most expensive rice comes from the US. Why? Why not from China or Japan?

I live in London with my Japanese wife and most of the rice sold in the Japanese shops here is also from the USA (California) or Spain. It is Japonica rice though and it is sold in bags often using the name Akita. Rice imported from Japan is sold here as well but is much more expensive and is probably only bought by Japanese expats with a cost of living contribution.
The Californian rice is not too bad and much cheaper, so I think the reason it is the only "Japanese" rice sold in Canada is simply the rules of an open market.

2. How is the production of rice in Japan regulated? Are there government subsidies for rice farmers? Are there import/ export restrictions?

There are subsidiaries and there are import restrictions even though the American rice is now also imported into Japan and you'll find them in cheap beef bowl restaurants, for example. I don't think Japan ever considered becoming a rice exporter, especially since a couple of decades ago the aim was to get rid of a lot of small rice farmers.

3. While in Japan, I noticed that most rice fields are relatively small. Are they mostly independently owned? Is there such thing as large, corporate rice producing companies in Japan?

I don't know too much about this, only that the family of my wife has a big orchard and at parts of it they grow their own rice. Like you, I have the feeling that lots of families in the countryside still have their acre or so to grow their own rice. The harvesting seems to be handled by big companies as in autumn you can see an army of most modern machines harvesting the rice which would have been much more a mixture of old and new machines if the harvesting was handled by the local farmers, especially when they only have a small crop.