Sorry, I just noticed that fare has to be bought 35 days in advance, so you've missed the window. It was from Hit Travel in Japan, and there are other fares available but not as cheap (and yes, the next lowest fare is on China Eastern). Here's the link, sorry you're too late to buy the lower fare:
http://www.hittravel.co.jp/air_prod_...ang=ENG&ra=SHA