They did their World War II service in secrecy, often alone or in small groups. For decades after, their work was classified, and they were forbidden to tell anyone. Even today, some of them still aren't comfortable talking about it.

Yesterday, though, veterans of the Military Intelligence Service got a bit of long overdue recognition: a plaque at the National Memorial Cemetery of the Pacific honoring the work done by more than 7,000 Japanese Americans who formed the unit.

"It's our legacy. It means somebody will always remember us," said 83-year-old Takejiro Higa, who was born in Waipahu and served as an interrogator of Japanese prisoners in the Philippines and Okinawa during the war.

The MIS members, many of whom came from Hawai'i, were an indispensible part of the U.S. victory in the war in the Pacific, speakers said. They worked as translators, interrogators, intelligence officers, radio message interceptors and undercover agents during the war, sometimes facing so much suspicion that they had to be assigned bodyguards. They often ended up walking into caves and bunkers, armed with nothing more than a knowledge of Japanese culture and language, to convince soldiers and civilians to surrender.

After the war, they played an equally crucial role in the reconstruction of Japan, work that may have helped forged the strong ties between Japan and the U.S. today, said retired Circuit Judge Frank Takao, president of the Hawai'i MIS Veterans Club. Later they also served in Korea, interviewing captured soldiers, many of whom spoke Japanese.

In all, they saved thousands of U.S. servicemen and countless Japanese civilians who were caught up in war. Gen. Charles Willoughby, intelligence chief for Gen. Douglas MacArthur, once said their work shortened World War II by two years.

Yet they went virtually unnoticed at home for more than 50 years, with recognition often going to their more famous nisei brothers in arms who served with the 100th Infantry Battalion and 442 Regimental Combat Team, which have memorial plaques at Punchbowl. It wasn't until the group earned a Presidential Unit Citation in 2000, and a 2001 TV documentary aired that the unit started to become more widely known.

"These were men raised with a deeply ingrained sense of Japanese traditions, but when it came time to choose, it was with a deep sense of patriotism and love of freedom that they volunteered for the American side," said retired Marine Corps Col. Gene Castagnetti, cemetery director.

For Higa, it was an easy choice. He was born in Hawai'i but lived in Okinawa from ages 2 to 16, when his sister convinced him to return home so he wouldn't be drafted into the emperor's army. A year later, he enlisted in the U.S. military and was sent to the newly formed MIS school in Minnesota. A few years later he found himself on a troop ship, about to participate in the U.S. invasion of Okinawa, just over a hill from where his grandparents had lived. "I had all kinds of time to think about that on the ship, but once the invasion began, I just did my job," he said.

Eventually, that job brought him face to face with several Japanese prisoners who had been his school buddies in Okinawa. They didn't recognize each other at first, but gradually it became clear that they were old friends who ended up fighting each other in a war.

"It hit me hard. It could have been me sitting on the other side of the table. Eventually we all had a big healthy cry of happiness together," Higa said.

"The nisei served with distinction and honor. Little is known that 19 nisei gave up their lives in the line of duty," said MIS veteran Ted Tsukiyama, an attorney and historian. "They validated the truism that Americanism is not, and never was, a matter of race of ancestry. Americanism is a matter of the mind, the heart and the spirit."

Reach Mike Leidemann at mleidemann@honoluluadvertiser.com.