Bangkok has many different types of people that live here. There are manny Thai (or course) but also some other nationalities. Most people think of foreigners just as European or American but actually there are so many Korean, Japanese, Indian and other foreigners that live in Thailand and Bangkok especially.
Today, I went to visit Japanese Town in Bangkok. Its a area on Thonglor 13 near Seen Space. I like it because there are many Japanese restaurants there with some fresh sushi, meat grill, etc. The price is high for some of the restaurants but in many the price is very reasonable and selection of foods is very high.
If you live in Bangkok and want to try a Japanese meal from authentic chefs, this is the best place to visit, and easy to get there from Thonglor BTS station on Sukhumvit RD!