"I realized as I got older that I knew practically nothing about this story," says Robert Asahina, the author of the new book "Just Americans: How Japanese Americans Won a War at Home and Abroad" (Gotham Books, $27.50).

"My father, who was in the Army, was not in the 442nd. I had an uncle who was in the 442nd, but I was not very close to him. So the story was brand new for me," said Asahina by phone from San Francisco, one of the stops on his book tour. "That's probably not the case in Hawai'i, but on the Mainland, the 442nd is not well known."

In Hawai'i, many may find it incredible that the story of the 100th Battalion, 442nd Regimental Combat unit, could be unfamiliar. But even here, these days the majority of references to the 442nd are found in obituaries. The overseas battles, the struggles with racism, the initial infighting between the Hawai'i and Mainland soldiers — the details are fading, like the "old soldier" cliche.

In "Just Americans," Asahina tells the story of "18- and 20-year-old kids" who volunteer to fight for a military that — at one point — won't even take them. They go on to become the most highly decorated unit in military history for its size and length of service. He frames their stories against the political backdrop of war, racism and relocation centers. He will read from his book today at Bestsellers, downtown.

"On the Mainland, the story that's well known is the story of the relocation, and that has so overshadowed the Mainland understanding of what Japanese-Americans did," says Asahina, who is currently a visiting scholar at the Asian/Pacific/American Studies Program at New York University. "The story of what they did as soldiers has really gotten lost. And my argument is that (it was) what they did as soldiers, the achievements of what they did as soldiers, that was actually responsible for freeing (Japanese-Americans) from the camps. That's a connection that I have not seen before."

When, in 2000, President Clinton upgraded 22 Asian-American World War II veterans with Medals of Honor, the story piqued Asahina's interest. After two years of initial research and meeting with veterans, he began a four-year process of research and writing, which included two visits to Hawai'i.

He interviewed "quite a few" of the surviving members of the group, including his uncle, who died shortly after. Asahina, who grew up in Ohio, says his family didn't discuss World War II in a personal context, because they were not as affected as others. Asahina's parents were not relocated.

"Many of my relatives had been through the relocation camps," he says, "but they never really spoke of it." Asahina says his uncle "was sort of a typical Mainland Japanese-American man, in that he really didn't have much to say. War had been a terrible experience for him, but he went on and made a good life. When I specifically asked what he went through or what he remembered, he was very reserved."

Asahina says he commonly encountered that reticence — until he got to Hawai'i.

"That was my experience, with the exception of the guys in Hawai'i, who were very eager to talk," Asahina says, chuckling. "They have that phrase in pidgin 'talk story' and they would get together and talk story."

The contrast could be attributed to the "difference between being the minority culture versus being the majority culture," he says.

When Hawai'i's Japanese-American soldiers departed for the Mainland, 15,000 people gathered at 'Iolani Palace for their send-off. At that time, Japanese-Americans made up nearly 40 percent of the Islands' population. They sent their boys — 10,000 of them initially volunteered — off with money, lei and good wishes.

On the Mainland, Japanese-American volunteers came from relocation centers, from families who had everything taken from them. Japanese-Americans on the Mainland represented less than "one-tenth of 1 percent." Asahina captures the amusing differences between the groups in a chapter called "Kotonk V. Buddhahead."

Eventually, they bond and in less than two years, the 442nd "had participated in seven major campaigns in Italy and France, received seven Presidential Distinguished Unit Citations, and suffered 9,486 casualties."

The 100th Battalion, 442nd Regimental Combat unit stands out in American military history as a segregated Japanese-American unit fighting to be recognized as simply Americans. Whether the burden of history initially weighed so heavily with each soldier remains unclear. But history, Asahina says, is not made with intentions.

What most struck him "was that in the end, regardless of what people said, or what their motives were, their actions ended up speaking louder," Asahina says. "What they ended up doing and why I called the book 'Just Americans,' is that they wound up acting like, just Americans.

"They took on the responsibility of citizenship and regardless of their background, or their culture ... they acted as individuals. They had freedoms' will. They made choices and their choices said, 'I'm an American just like you guys.'"