Travel from Matsumoto Japan to Kazeya Hotel in Shin-Hotaka, Okuhida

Kazeya is in Shin-Hotaka, and Nohi Bus appears to have a direct service from Matsumoto to Shin-Hotaka; unfortunately it runs for only a few days around New Year's. The rest of the time, you'll need to change buses at Hirayu (????) to Shin-Hotaka Ropeway (?????????). (Schedule here: the connecting bus starts from Toyama, on the Japan Sea coast.)

Unfortunately, while it appears this bus runs past your hotel, it does not stop and the nearest stop, Shin-Hotaka Ropeway, is a few km down the road. You might be able to convince the driver to drop you off, but I wouldn't count on it, and flagging the bus on the return trip will be even harder.

The good news is that most Japanese onsen ryokan in remote locales offer a pickup/dropoff service from the nearest bus/train station, either for free or a small fee, so I would advise you to contact them directly.

That said, having visited the area myself, I would advise you to seriously consider renting a car. Public transport in this neck of the woods is very limited, making it tough to actually visit any nearby attractions, and the ¥5,760 return bus ticket will likely pay for a day's rental.

Updated following sage advice from fkraeim, whose Japanese bus schedule parsing skills clearly put mine to shame.