North-East Hokkaido is a virtual playground for photographers/adventures/visitors. The Sika deer, in the summer, are scarce in the winter; they can be found commonly, the coastline, where there is dry grass to eat. Knowingly it does not have much nutrition, but it keeps them going till spring arrives.
Nemuro to Rausu is 138km; this stretch is your best chance to spot/photograph the Sika Deer while in Hokkaido. A good place to start is Notsuke Peninsula; they also have a visitor center. It is rare that I go down this tourist path, but there is a fantastic spot for “sunset photography, on the Notsuke Peninsula.”
This shot I took while I was leading a Hokkaido Winter Phototography Tour we spent over an hour with an estimated 1000 sika deer. Timing is everything to capture this shot, and the location is off the tourist track and not easily traversed.