Originally Posted by solomita
My interest is that I'll be arriving into BKK international terminal at 9:30PM, flying back out the next morning at 8:20AM, again international. Flying in on Thai Air, out via JAL. If it's possible to check my bags straight through and not have to worry about checking in the next morning, that would be wonderful. But, it's Star Alliance connecting to OneWorld.
You will be able to check your bags through from TG to JAL. If you remain in the airport security (including the day rooms), then you will not have to "enter" Thailand by going through immigration. But Bangkok is too fun of a city to spend 11 hours at night in an airport terminal!
I suggest you clear customs and have some fun in Bangkok, then come back for your morning flight and sleep like a baby to Japan. Whn you check in with JAL, show then your bag tags so they can see you have baggage and link it to your reservation on their system.