OK, so what's happening here is that UA has pulled all of their discount WAS-SIN business class fares, and most of their discount WAS-TYO fares. There's nothing published cheaper than a D fare on WAS-SIN or a Z fare on WAS-TYO. If you wait, they may republish them. If you don't want to wait, you can get a P fare on EWR-SIN or a Z fare on BWI-SIN.

Unfortunately, ANA doesn't appear to fly CAN-KIX; if they did, you could take advantage of a CAN-WAS P fare and get the total down to about $4400 (from EWR) or $5600 (from BWI). If you can substitute CAN-NRT, and then take a separate flight (or, better yet, train) to Osaka, you can get those fares. (ETA: by combining the CAN-NRT flight onto the same ticket as US-SIN and NRT-IAD).