Hilton HHonors is about to launch their next 50% off Flash Sale lasting 72 hours for stays in Japan & South Korea.
The sale should go live later today (while I am on a flight) but it appears that the rate plan is already loaded to some properties.
You can access the Flash Sale page here.
Note that the valid stay dates of this promotion are currently unclear. Properties may have discounted many of their room types including suites by 50%.
Rate Display For Hilton Tokyo:
The 50% off rate plan is already live for this property. This is for a weekend night in August.
I have separate post up once the sale has gone officially live and I have the terms and conditions available.
Could be worthwhile to check the prices in the meantime, however. Sometimes the discounted inventory get booked up fast if the sale is a good one.