4 Feb - booked a twin bed at Mecure Sapporo at Accor site, 4 nights ¥35,400
4 Feb - submitted a BRG using Kayak ¥33,300
7 Feb - email from Mecure Sapporo to say they received my BRG and will look into it.
7 Feb - emailed the screenshot to Mecure Sapporo from Kayak stating the total rate for 4 nights @¥33,300. Did not state individual nights.
8 Feb - Email from Mecure Sapporo stating claim approved. New rate ¥29,970 inclusive of taxes for 4 nights.

Not to much savings but a successful BRG nonetheless.