[Nyororin]

I can`t give you direct advice on reservations, but if you`re going to be staying in a hotel - why not do the reservation through the hotel?
We have been to multiple events around Japan, and have always asked the hotel to make the arrangements when making the room reservation. Even the bottom of the line business hotels will make arrangements for that sort of thing for you. Some will even add the price of the reservations/tickets/etc into the full cost of your stay.