The jobs were first created as Nagano began to pull away from the JET Program, and they are often occupied by 5-year JETs who weren't quite ready to go home. But, the positions are open for anyone to apply.
However, because the package is nice and there is no shortage of applicants each year, the qualifications are steep. For starters, you need to be in Japan and have a valid landing permission for work.
Job Title: 外国語指導助手 (Assistant Language Teacher)
Type: 12-month contract employee, renewable
Qualifications: Living in or near Nagano prefecture, English teaching experience, valid work "visa" (landing permission)
Working Hours: Same as JET (Approximately 8 to 9 hours per day, Monday to Friday)
Remuneration: Monthly, 300,000 yen
Insurance: Yes, Japanese national insurance deducted from salary
To apply, you'll need a Japanese and English resume, a 1-page essay, and results of a health check.
The contract period is also unusual and deserves mention: The job runs from August to July, on the same timeline as JETs. Nagano appears to be keen on retaining experienced ALTs in their high schools, so contract renewal seems likely here.
The site to watch is the ALT Hiring Page of the Nagano Board of Education website. In previous years, the notice has been posted late in April, and the deadline for applications is in mid-May.