Supplementary Provisions, Article 4

①A person for whom an entry under paragraph (1) of the preceding Article has been made (excluding a person for whom an entry under the following paragraph has already been made) may request the mayor of the municipality of domicile to change the characters indicating the reading of the characters used in the former surname pertaining to that entry to other characters; in this case, the person making the request must submit a document certifying that the reading indicated by the characters pertaining to the request is in general use as the reading of the characters used in that former surname, except where the mayor of the municipality of domicile finds that there are special circumstances.

②The mayor of the municipality of domicile who has received a request under the preceding paragraph is to enter in the certificate of residence the characters indicating the reading of the characters used in the former surname pertaining to the request, as the kana reading of the former surname; in this case, for the application of Articles 30-13 and 30-14 of the Order for the Enforcement of the Residential Basic Book Act and other provisions of laws and regulations to the person for whom that entry has been made, the characters so entered are deemed to be the kana reading of the former surname.