Niseko-Hirafu is located in the northern island of Hokkaido (Ski Japan Guide Hokkaido Location guide here).    From Sapporo by car, follow Route 230 via Nakayama Pass for approx 2 hours 30 minutes (92km).  By rail take the JR Hakodate Honsen Line, getting off at Kutchan Station - this will take about 2 hours 10 minutes.  The resort has shuttle buses running through the town approximately every 15 minutes - just raise your hand to stop the driver and get on!  Very convenient!  The buses run from 8:30am until 9pm each day in the season. 

For more information on Niseko-Hirafu check out the following resources: