This 2019 file photo shows the building housing the Tokyo District Court and Tokyo High Court in Tokyo's Chiyoda Ward. (Mainichi)

TOKYO (Kyodo) -- A Japanese high court ruled in a recent case that the requirement for genital appearance to be altered as a condition for the approval of official gender change for transgender people was "possibly unconstitutional" depending on individual cases, it was learned Tuesday.

The Tokyo High Court said the situation brought by a transgender woman was "unconstitutional," approving on Oct. 31 a gender change for her. According to the decision, the appearance of the petitioner's genitalia had not changed despite around 27 years of hormone therapy.

Japan currently demands the genitals to physically resemble those of the opposite gender among various requirements for people who want to change their official gender.

The high court said the appearance requirement effectively forces those who could not meet it through hormone therapy to undergo surgery and that this went against Article 13 of the Constitution, which guarantees individuals' freedom from "invasion into their body against their will."

However, the court stopped short of calling the current requirement itself unconstitutional, noting that "the legislature should discuss whether a revision to the law is necessary."

In general, a person born a woman can have their genitals appear male through hormone therapy, but for a man to have female-looking genitalia, surgery is almost always needed.

The petitioner applied for a gender change with a family court in January, but was denied due to the genitalia requirement, before appealing to the high court.

The Japanese law on gender dysphoria stipulates that those wishing to change their legal gender be no less than 18 years old, unmarried, have no child who is a minor, have no functionable reproductive glands, and have a physical appearance of the genitals that closely resemble that of the opposite gender, in addition to a diagnosis of gender dysphoria from at least two physicians.

In October 2023, the Supreme Court struck down the sterilization requirement as unconstitutional, but withheld a decision on the appearance requirement.