There is over 10 ice falls in Sounkyo. The Biggest ice fall(Ginga fall) is over 100m.
Most famous ice climbing area in japan is here.

 End of December to middle of March (depends on ice condition)

Guide fee
 1person 40000 yen / 1day
 Group for 2person 25000 yen each person / 1day
 Group for 3person or more, please ask by e-mail.

Rental gear
 ice axe, crampons, helmet, harness, etc.... 1000yen each item / 1day