Real quick I don't know how many jobs they have for non-Japanese speakers, but if you're on work holiday or have a visa try
Abucha, a restaurant in Hirafu. That link is in Japanese but they have English speakers who can review your application via email. They are hiring 50 this year and I think there's still 20 more slots. Pretty sure they also have dorm-style accommodation in Hirafu for their employees. Good luck.