Tai is a commonname containing a variety of different fishes in the Pagellus catagory. The English commonname is (red),(blackspot) sea bream. I think this is not a very prominent fish in the US since I don't see them being advertised a lot in Japanese restaurants here.
Probably one of the reason it did not get as popular in US is because of its inflexibility in the use of the fish as a cooking ingredient. It is a shiromi (white meat fish) and is mild in taste. Since sashimi in US has to be flash frozen before consumption, the taste would just be quite undesirable to consume as a nigiri sushi or sashimi. It would not be a good ingredient to make a chef's creation role either. The texture is quite chunky, and since it is not a fatty fish, you can't really bring in extra flavour in a fish. The next best thing besides making it in nigiri sushi might be grilling it with a sweet sauce.
Probably you should eat this fish either very fresh or don't bother to eat it at all. It's hard to find a good one in sashimi grade.