When concluding employment contracts with new employees, employers must clearly state employment conditions such as wages and work hours (Labour Standards Law, Article 15, paragraph 1). Of the 12 specific items that must be stipulated, matters concerning the following must be specified in writing and a copy provided to the employee:

1. duration of employment,
2. work location and job description,
3. work hours,
4. wages,
5. retirement.

Also among the items that must be stipulated are employment regulations. A copy of the business' employment regulations is to be provided to the employee, with the portions that apply to the employee clearly indicated. In addition, any matters that are not listed in the employment regulations must be clearly stated in written form in a separate document. As a general rule, the above matters are to be specified at the time the employment contract is entered into. Should any of the stipulated employment conditions differ from the actual working conditions, the employee may cancel the employment contract, effective immediately (Labour Standards Law, Article 15, paragraph 2). For details on the conditions to be specified, please see below.

For more information:

Chapter 2 Labour Contract, Labour Standards Law (548KB)
Specifying Labour Conditions