Why not just learn Japanese? It's a long flight
Automatically Appended Next Post: In all seriousness it depends how much time you have.
Tokyo is one of the great cities on Earth and well worth exploring, and even if you have weeks, Kyoto is just 3 or 4 hours by bullet train.
I frankly would not use precious luggage space and weight for an army. Maybe a small Kill Team.
It could be worth googling Warhammer Tokyo just to see what's out there. There was a
GW store in this massive anime/manga mall in Nagano that was fun.