Contract labor in Japan.
In previous posts, it was noted that there are two classes of employees, those hired to relatively permanent positions (about 20%)-trained technical or professional employees, and the majority, about 80%, of workers hired under time-limit contract.

"..........The employer is free to hire somebody by a fixed term contract so long as its term does not exceed one year. The employer is also free, at the end of the term, to renew the contract or not. The contract expires by itself and the employer does not have to terminate or oust the employee. The Labor Standards Law does not address such insecurity of employees under a fixed term contract." [Courts have modified this slightly through decisions]

A laborer under such a contract has no expectation of re-hire. This tends to make these laborers extremely docile in order to get on the 'good side' of the employer so that the contract will be renewed for another term.

The contracts (more than 10 employees) are written, the laborer knows the conditions of his employment. There may be a union, setting collective bargaining rights.
Some thirteen typical contracts are enumerated under the Civil Code.

[Contracts are much less inclusive of the types of protection that labor has in North American and most European countries].

From: "Similarities and Differences between Labor Contracts and Civil and Commercial Contracts: Japan Report."
Hiroya Nakakubo