>>2791257

My last trip I used exclusively booking.com. I'm too much of a sperg to just walk in and ask.
Obviously if you are there during super busy periods like Golden Week you would need to plan ahead; I plan my trips specifically to avoid peak times.

Also I never stayed in prime areas like Shinjuku/Shibuya/Kyoto etc. The more popular an area the less likely you'll get good deals at the last minute.