Hello Cliff,
Looking to the propagation forecast using
it really seems much harder from your QTH to get to Japan than it is from mine (Grid JN48nr).
But, taking into account your antenna situation, I would estimate that you have the highest propability for a QSO on 17m and 15m between
20:00 UTC and 03:00 UTC.
This is (very) early in the morning until noon in Japan -- so it might be possible especially on weekends.
It may help to announce your activity ("QRV INFO") here on the list and to spot yourself on clusters (with note: "CW CQ JA").
CU 73
Tom DF7TV