Interesting note - I had two rooms booked for 4 people total on Prive rates (upgrade confirms into Twin Bed Deluxe) but one pax dropped out and I was hoping I could consolidate 3 people into one room. Some communication back and forth about whether it was acceptable to put 3 people into the Twin Bed Deluxe as the original 2 Twins base room booking only accepts 2 people. Ultimately it was approved, but with 7400 yen extra person charge and another 7400 yen for the rollaway, per night. Extra ~15K yen per night on a 27K yen booking is a bit steep, but alas.