Originally Posted by
jpdx
This was actually super easy -- Kayak.de to Expedia -- the trick (for Japan in general) is to book way out, when the hotels have loaded nothing but ridiculously high rates. My actual stay dates had rates of ~25k yen on SPG.com, and while you'd likely still be able to find a lower competing rate, you'd probably end up in the 20k range after discount. My most successful BRGs are booked 8-10 months out.
Not to go off topic but this is normally my strategy for Japan too but oddly enough the migration to the Marriott booking platform has messed it up in some cases. Weird low rates showing up at Prince Gallery super far out when they normally would have some ridiculous high rate, and a room normally not bookable with cash now has a cash rate. Same for the Sheraton, low rates even way out at the end of November.