You could try this website. I'm pretty sure they used to offer discounts if you were buying sets for a school, but I'm not 100% sure if they do or if it was even this site that used to. Anyway, the sets here are a bargain don't know about shipping to Japan though. Good Luck!
http://www.chessusa.com/category/CHESS_COMBINATION_SETS.html
I teach at an elementary school in Japan and recently discovered that a lot of kids at my school like to play chess. Currently we've been using the little dinky pieces from a novag citrine that I own and a printed paper chess board, so I thought it'd be nice to pick up a silicon chess board and some tournament pieces. The sites I've seen sell the board for around $15 and the pieces around $7 but the shipping $132. The question: where is the best place to order online and not take it in the rear on shipping?
BTW, I have looked here in Japan but other than themed sets, like One Piece and Gundam, haven't seen anything like what club players have access to back home.
Thanks for the help!