Where are the best places to buy discount business class tickets for flights originating in Japan to Europe or North America?

Looking at the airlines websites, they don't seem to offer any discounted business class fares.

I went to JTB and they hooked me up with a reasonable Tokyo-London roundtrip business class fare for 378,000 (on Alitalia), but there must be some better deals than this.

By the way, I recently relocated to Tokyo and I'm new to this forum, but I really have enjoyed what I have read so far.