There are cheaper periods, but at least from Japan - US, cheaper doesn't mean cheap and fares have been consistently high for some time.
Wife and I went to ORD in November - Osaka - ORD was $1500, but ICN - ORD was $800 ($1000 including KIX-ICN segments). These were both on United without crazy layovers. Looking at random times next year, I see the exact same thing - from ICN is substantially cheaper.