It is not required to even sign or seal in employment contract according to Labor standards Act in Japan. It request just clear understanding and agreement between employee and employer for employment contract. Although it is not mandatory to affix seal or sign, it is most commonly executed by both employee and employer. In case any trouble between employer and employee, the employment contract with both seal is valid to protect company against any legal action by employee, especially with company seal. Company seal here is same as representative director’s seal registered in legal bureau.