From Sunday Dec 16th you can purchase special 3day bus passes from the main tourist office by the train station.
These passes cost 2,700yen and can be used to ride the Mt Myoko shuttle as well as the Lotte shuttle & Madarao shuttle.
Usually a one day return to Madarao/Lotte costs 2,000 so this is a good deal if you plan to spend a few days visiting other resorts.
If coming by train you can walk across to the tourist office to pick up a ticket.
There are a limited number available (400).
The winter shuttle starts operating from December 23rd.