I think this is a Bull-headed Shrike. The photo is a bit blurry, so it's not easy to see if the breast is scaly, and we can't see the back or wings, so it could be male or female. (If you have other photos showing the back, then by all means post them.)
In Japan, the main Brown Shrike subspecies is ssp superciliousus, which has a prominent supercilium which reaches around the front of the head. The other less common one is ssp lucionensis which has a grey head.
The 'Brown' name seems to refer to the coverts and tail rather than the front of the bird.
Also, I don't think Brown Shrike has such a strongly coloured breast or that the breast colouring would reach so high up on the throat, but this is normal for Bull-headed.
Brown-headed should already have passed through anyway, I think, although with the warming climate, who knows?
For what it's worth, I have never seen Brown Shrike outside Okinawa, whereas Bull-headed are extremely common, but it may be that Brown Shrike (which is not resident, except maybe in Okinawa) breeds at higher elevations that I usually go. Anyway the birds in Okinawa (I have seen both supercilousus and lucionensis, though only a couple of times) seem very pale when compared to local Bull-headed.