I've been there a number of times, most recently in 2007. Even in October, I recall nighttime in Kyoto feeling a bit stifling, but it was an ideal time to visit the northern island of Hokkaido!
The big stores like BIC Camera and Yodobashi kinda throw me off balance, and that seems to be by design. Only a fraction of these stores is actually photographic equipment, but not to worry, there's still plenty to see. But AFAIK, they don't sell vintage gear, at least I've never seen any. One "danger" is getting excited over items you can readily get back home, but which may not be presented as enticingly there, so you may simply never have noticed them. For me, it helps to have specific objectives when I shop, otherwise, I just wind up gawking at everything, and deciding on nothing.
Haven't done much shopping for used gear, but even in pre-pandemic times, I recall prices similar to, or higher than USA, but the selection may be better. Have seen a whole lot of Leica M, wouldn't be surprised if there's been a glut of the things dating back to the bubble-economy years. Might be fun to browse the junk bins of shops like Hard Off, but I've never been. I have browsed their USA outpost (Eco Town) and that was pretty cool. Seem to recall seeing a plastic film SLR or two, maybe some cheap 50 mm lenses being sold as junk. Do it enough, and I imagine you could score a deal on good a fixer-upper or an obscure cable.