There are a number of ski rental places around so finding your preferred ski equipment shouldn't be a problem.
Our recommendation for ski rental is a local company Aoyama Sports. They have 3 places in Akakura Onsen.
There are also a few ski schools around.
Our recommendation is the local ski school Yodel. They have both Japanese and English speaking instructors.
There is also Myoko Snowsport.
Its really just finding the one that suits you.