A revised family register law in Japan, requiring the inclusion of phonetic readings of personal names, will come into force on May 26 this year.

In line with the revision, citizens who wish to register phonetic readings that differ from those listed on their certificates of residence must notify their municipal governments within one year of the law's implementation.

Certain restrictions will apply to unconventional name readings that significantly deviate from traditional interpretations of kanji characters.

For the time being, however, the specific criteria for these restrictions have not yet been clarified. The Justice Ministry aims to issue guidelines by March at the earliest.

The family register system records and certifies an individual's familial relationships from birth to death. It includes information such as the individual's name, registered domicile and family relationships, but it does not currently record the phonetic readings of names.

Municipalities determine the readings of personal names for certificates of residence on the basis of the entries in birth notifications. As this practice lacks a legal basis, however, the readings are not included in the family register.

The revised law, enacted during the 2023 ordinary parliamentary session, aims to streamline the management and retrieval of personal data by advancing the digitalization of administrative processes.

With the growing prevalence of unconventional names with unclear pronunciations, the law introduces a new standard. It defines permissible pronunciations for entry in the family register as those "generally recognized as the pronunciations of the characters used in personal names."

Once the revised law takes effect, municipal governments nationwide will notify residents by mail of the phonetic readings of their personal names as recorded in certificates of residence and other documents, which are planned to be entered in their family registers.

If any discrepancies are found, residents must report corrections to the authorities, either via the portal for the My Number personal ID card for taxation and social security, by mail, or by visiting government offices in person.

The determination of whether a given reading is considered common will be made at municipal government counters. While specific criteria have yet to be finalized, the Justice Ministry intends to call for a flexible approach that respects Japan's naming traditions.

Japan has a longstanding tradition of allowing diverse name readings that deviate from the conventional readings of kanji characters. For example, the character for tomo in Minamoto no Yoritomo, the 12th-century warlord who established the Kamakura shogunate, is typically read as asa or chō.

Experts note that some readings, uncommon when first adopted for personal names, have gradually become more widely accepted over time.

In keeping with this tradition, the Justice Ministry plans to require applicants to provide explanations for submitted readings of characters that are not found in the list of common-use kanji or in dictionaries.

In principle, a personal name reading will be approved even if it deviates from the traditional reading of a kanji, provided that it is already in use for personal names. Unconventional examples include the character umi, meaning "sea," being read as "Marin" to suggest "marine," and the character kishi, meaning "knight," being read as "Naito." Such readings are expected to be approved for individuals who have already adopted them.

Meanwhile, no decision has been made regarding the acceptance of names derived from manga and anime characters, such as Pikachu. The Justice Ministry plans to continue discussions on the issue, focusing on whether such names are appropriate as children's names.

There are exceptions to the readings that can be listed in family registers.

The ministry provided three examples: The kanji meaning "high" cannot be read as hikushi, which would imply the opposite meaning of "low"; Taro, a widely used name, cannot be read as Jiro, another common name, to avoid confusion over whether it is a mistake; and Taro cannot be read as George or Michael, as no connection to the kanji used can be identified.

Additionally, the ministry will reject readings deemed an "abuse of naming rights," or those that deviate significantly from common sense, officials said.

Family court approval is required to change the readings once an application for registration has been submitted. The ministry is urging individuals to carefully consider their chosen name readings before submitting their applications.