We went on an independent tour of Japan in January 2019, renting a car in Kushiro and driving up to the end of the road north of Rausu, seeing lots of eagles, cranes and the Blakiston Fish Owl as well.  Since we were on our own, I have no guide information, but do have other (somewhat out of date) ideas.  jimforjim (at) yahoo.com.
HTH, Jim