I've never tried before and I can't find anything specific about it in the terms of the rate. All it says is that ID is required which is expected. Any issue booking a rate under my wifes account but I'm the one with the corporate rate? I'd imagine most places wouldn't even care but this will be in Japan where they are likely to follow the rules to a T. Last thing I want to deal with is us getting there and finding out that's a big no and having to pay the standard rate.

edit: I should clarify that it is a rate valid for leisure travel. It's not some rate that's specific only to business travel.