Hilton are running a pretty spectacular flash sale in Japan,
offering a full 50% off at various properties.
You need to book by 19 May, but the sale rates apply to stays any time up to 30 December 2017.
Given the high cost of hotels in Japan, particularly in central Tokyo (and both the Hilton and Conrad Tokyo are included in the sale), this is a great opportunity if you can make it work for you.