The Naha Family Court on Wednesday approved an application by a transsexual to alter her officially registered sex to female under a new law, a support group said Thursday.

The approval is the first to become known since legislation took effect July 16 enabling people with gender-identity disorder to change their sex listed in their family registry under certain conditions, according to gid.jp, the support group.

Gid.jp did not release the applicant's name, but said she is a resident of Okinawa in her 20s.

It said the woman had been uncomfortable with her biological sex since she was young and desired to live as a female. She underwent sex-change surgery last year, it said.

"We did not expect that an approval would come so soon," gid.jp representative Ran Yamamoto said.

"I am very happy to know that the courts will really approve the changes," said Masae Torai, 40, who has applied to the Tokyo Family Court to alter his registered sex and is waiting for approval. "Now that the precedent is set, I can be at ease."

At least a dozen other applications have been submitted to family courts across Japan, Torai said.

Under the new law, people diagnosed by at least two doctors as having a different psychological makeup from their biological sex can apply to change their registration. They must also be aged 20 or older, be unmarried, have no children, and no longer have functioning reproductive organs due to undergoing a sex-change operation.

A estimated 7,000 to 8,000 people in Japan suffer from gender-identity disorder, according to Yamamoto.