In principle, Japanese visa will be issued to an applicant, when he/she fills all of the following requirements and the issuance is regarded as reasonable.
a) The applicant possesses a valid passport and is entitled for the re-entry to a country of which he/she is a national or citizen or a country of his/her residence.
b) All submitted documents shall be authentic, completed and satisfactory.
c) The activities to be engaged in while in Japan, or the civil status or the position of the applicant, and the period of stay shall meet the requirements for the status of residence and the period of stay stipulated in the Immigration Control and Refugee Recognition Act. (Cabinet Order No.319 of 1951. hereinafter referred to as "the Act")
d) The applicant shall not fall under any of the items of Article 5, Paragraph1 of the Act.

Japan Visa types
Japan Visa FAQ
Nationals of Countries and Areas with Visa Exemption arrangements
Alien Registration
Re-entry Permission
Special Residency Requests
Immigration