While a re-entry permission is, in general, valid only for one time, a multiple re-entry permission may be given to persons who need to make trips outside Japan frequently.
The term of validity of a re-entry permission is limited to within the date of expiration of period of stay and the maximum is 3 years(4years in the case of special permanent resident).
  When a foreign national who has left Japan with a re-entry permission has justifiable reasons, such as disease, for being unable to re-enter within the valid term of the permission, he or she may be granted extension of the validity within a period of one year and not exceeding four years(5years in the case of special permanent resident) from the issuance of the re-entry permission at a Japanese embassy or consulate abroad.       Needless to say, it is impossible to extend the validity beyond the authorized period of stay.

Documents to be submitted
①For reason of birth:
○APPLICATION FOR RE-ENTRY PERMIT
                                                                                                                2 copy
○Documents explaining the reasons why the applicant does not have a passport, if he or she does not carry one (excluding a stateless person or an alien from the country which is not officially recognized, etc.)　　　　
                                                                                  　　　　　　　　　　　　　　　 1 copy
○Certificate of alien registration etc
                                                                                                        1 copy each
○Materials supporting the necessity of re-entry issued by recipient organization (e. g. in case of status of residence of “Pre-college Student” or “Trainee”)
                                                                                                        1 copy each