A Tech License grants 10M phone permissions between 28.300 and 28.500, which is basically useless with propagation the way it's been (terrible.) My last 10M contact was into Japan last summer on my beam and 100 watts. That's the ONLY time I've heard Japan in 5 years on any band sitting here in the midwest.
I would say that 15 meters is your best bet for working JA...that’s where I have about 20 JAs over the last couple of years. Also have them confirmed on 80, 20, 17, 12 and 10 during the same period, phone and CW. Still need to catch them on 30 and 40 meters.
That’s with wire antennas and I don’t own an amp.