A young boy who believes he was born the wrong sex was allowed to enroll as a girl at an elementary school in southwestern Japan, a school official said Thursday.

The seven-year-old boy entered the school as a girl in April 2005 after he was diagnosed with gender identity disorder at age six, a spokesman for the local school board said. The Japanese school year starts in April.

The official, who spoke on condition of anonymity to protect the identity of the boy and his school district, said the boy's name is listed with girl students and that he is allowed to join the girls' gym class and use the girls' bathroom. The boy, who's in the second grade, wears a girl's swimsuit at the school pool.

"At this point, we are relieved that the child was accepted into first grade and is being raised in a healthy manner," the official said.

The school is in the southwestern prefecture of Hyogo, about 270 miles west of Tokyo.

The school's decision is highly out of character for Japan's public school system, which is known for learning by rote and has little tolerance for children who don't fit in. Awkward children can be mercilessly bullied by other students.

The Tokyo Shimbun newspaper reported that the boy's name could be both a boy's or a girl's, and that he had preferred girl's clothing from a young age. The school has not told other parents about the switch, and it was unclear whether any of the students knew the boy's gender.

The school official said that there had not been any complaints from other students or from the boy's parents since his enrollment. He said the school district would watch his case closely and reassess the decision as the boy reaches puberty.

Katsuki Harima, a psychiatrist specializing in gender identity disorder at Tokyo Musashino Hospital, said the decision to allow the boy to enroll as a girl seemed appropriate, but would get complicated as he grew older.

Harima said the boy is not old enough to really determine whether he has the disorder. A boy who behaves like a girl does not necessarily mean he has gender identity disorder, and he could discover as he grows up that he wants to be male, Harima said.

"I am a bit concerned about the child's future," he added, saying he has never heard of a case like this before at an elementary school. "There will be problems."