what is the cheapest airline from japan to beijing?

You can try this http://www.no1-travel.com/ the staff can speak english so try to call them to ask the cheapest ticket to go Beijing.

It cost only about 20,000 Yen to Beijing for super saver sit.

We flew from tokyo to beijing on a north western flight. it wasn't too expensive. No. 1 travel is a good bet also HitTravel, all based in tokyo. Check out this weeks metropolis, always good deals in there

I'm told this is a good site for travel

http://www.elong.net/flights/default.aspx?g=TjInternational

I did a quick search for Beijing to Tokyo and found one for 2630 RMB

My friend just used it to get a cheap ticket to korea, but i hear it's good for most places. Last time i used it he pulled up a list of all flights for the next month from all airlines and associated prices.

Re Superduper:

"It cost only about 20,000 Yen to Beijing for super saver sit."

Gosh, that's still pretty expensive for a "super saver"! In Europe, a "super saver" costs more like 4,000 Yen round trip! And that's from London to Warsaw, which is 2/3 the distance from Beijing to Tokyo but only 1/5 the price!