Naha District Court, which also houses the Naha branch of the Fukuoka High Court on Okinawa, is pictured on Dec. 20, 2024. (Keishi Koja/Stars and Stripes)

NAHA, Okinawa — A U.S. airman convicted on Dec. 13 in Japanese court of sexually assaulting a 15-year-old girl last year on Okinawa has appealed the verdict.

Senior Airman Brennon Washington, 25, of Kadena Air Base, appealed on Dec. 13, the same day the verdict was rendered in Naha District Court, a spokeswoman for the court said by phone Friday.

Washington was sentenced to five years in prison with hard labor after a three-judge panel found him guilty of kidnapping and sexually assaulting the girl after picking her up in a Yomitan park and taking her to his home on Dec. 24, 2023.

The case will be forwarded to the Naha branch of Fukuoka High Court, the spokeswoman said.

Some Japanese government officials may speak to the media only on condition of anonymity.

Washington is in Japanese custody, the 18th Wing at Kadena wrote in an unsigned email Friday.

Under the Japanese legal system, a high court reviews the trial court proceedings and judgment to ensure compliance with procedural law and look for errors in the interpretation or application of law, excessive severity or leniency in the sentence or errors in fact-finding.

Usually, proceedings are restricted to oral arguments by attorneys and prosecutors and do not involve reexamination of witnesses or other evidence.

The court can either dismiss Washington’s appeal, reverse the original judgment, reverse the judgment and remand it back to Naha District Court for a retrial, or render a new judgment. However, the new judgment cannot be stricter than the original.

The case against Washington and unrelated charges of attempted sexual assault against Marine Lance Cpl. Jamel Clayton unleashed discontent within the Okinawa government and prompted a mass demonstration by Okinawa citizens. It also led U.S. Forces Japan and bases on Okinawa to impose restrictions to curb excessive drinking by U.S. troops across the country.

In the wake of Washington’s March indictment, undisclosed until June, Okinawa Gov. Denny Tamaki accused Japan’s central government of withholding information from Okinawa prefecture about criminal allegations against U.S. service members.

The Okinawa Prefectural Assembly also called for changes to the status of forces agreement governing the U.S. military population in Japan.

In its verdict, the court gave credence to the girl’s testimony, some of which was backed up by security cameras in the Yomitan park.

The judges also determined that Washington was aware he did not have consent based on the girl’s repeated requests for him to stop. They found that Washington invited the girl into his car with the intention of “acting indecently.”

The girl testified on Aug. 23 that she used English, Japanese and hand gestures to tell Washington she was 15 and that Washington at his home kissed her with his tongue and penetrated her with his fingers and tongue.

She had to repeat “stop” in English and Japanese several times, she testified.

Washington admitted in court on Aug. 29 that he was intimate with the girl, but with her consent, and that he did not penetrate her. He also testified that he believed the girl was 18.