He'll be in a dark suit, with his only son at his side as best man.

She'll be in a white suit, with her only daughter at her side as maid of honor.

But when they promise to love, honor and obey as they take traditional wedding vows eight weeks from now, it's still undecided whether the new Mrs. Daniel K. Inouye will actually take the senator's last name.

"We're still trying to work that through," said Irene Hirano, the petite and stylish 59-year-old Los Angeles museum executive who accepted a marriage proposal a year ago from Hawai'i's 83-year-old senior senator.

"She has her professional career," he said, adding in jest that they could have a card saying "U.S. Sen. and Mrs. Daniel Inouye," with the caveat "also known as Irene Hirano."

On May 24, the couple will be married in a small, private service in Los Angeles, with only their families present. Inouye said last week that his son, Kenneth, is already beginning to stress about arrangements.

"Don't worry," the senator reassured him.

"We're keeping it small and simple," added Hirano. "I still have to do the flowers."

In traditional fashion, Inouye asked Hirano's family, including her 83-year-old mother, Jean Yasutake, two younger sisters and a brother, for permission to wed Irene, a divorcee.

"They approved," Inouye said, "but one sister looked at me and said: 'How often do you expect to be with her?' I said, 'Six times.' She said, 'Wonderful, six times a month,' and I said, 'No, six times a year.' "

But his son's words of approval were the ones he needed to hear.

Ken, the senator's only child, was especially close to his mother, Margaret "Maggie" Inouye, who died in 2006 after succumbing to cancer. She and Inouye were married 57 years.

"The most important reaction is the one from my son," Inouye said. "And he said, 'Dad, you outdid yourself.' "

After the wedding ceremony — chosen to coincide with the start of the U.S. Senate recess — the couple will take a five-day honeymoon and then fly back to Washington, D.C., where Hirano is scheduled to give a major speech.

But already the senator has begun indoctrinating his bride-to-be with certain sacred Hawai'i customs.

"I introduced her to Zippy's," he said, with a chuckle. "And New Eagle Cafe."

The budding local girl ordered Portuguese sausage and eggs. And finished it all.

"One thing about Irene is she just doesn't nibble, she finishes," said an admiring Inouye as his bride-to-be shot him a stunned glance.

With the marriage barely two months away, Hirano has been winning hearts in Hawai'i among those familiar with her warm manner, easy laugh and list of accomplishments.

Since earning bachelor's and master's degrees in public administration at the University of Southern California in the early 1970s, she has gone on to leadership positions in women's health and cultural exchange programs, as well as national governance positions with such prestigious institutions as the Smithsonian, Ford Foundation, American Association of Museums and the National Trust for Historic Preservation.

For the past 20 years Hirano has been president and CEO of the Japanese-American National Museum based in Los Angeles, building it from debt-ridden hope to solvent reality. She led fundraising campaigns that garnered $65 million and 65,000 members, built an endowment, and has overseen a multimillion-dollar expansion.

Richard "Dick" Kosaki, chancellor emeritus of the University of Hawai'i-Manoa, who is now on the museum's board of governors, said Hirano has been the powerhouse behind the museum's success.

"She's done a magnificent job in bringing it to life," Kosaki said. "And they've reached out to the Caucasian, African-American and Hispanic communities. She's done a terrific job. ... Dan has admired her skills and abilities."

The museum sponsors cultural exchange programs, cutting-edge exhibits, and has provided the Japanese-American community a chance to explore its own unique history and assist other groups to explore theirs.

"I think he's very fortunate to have found a woman like her," said attorney Colbert Matsumoto, chairman and CEO of Island Insurance Co., who works with both Inouye and Hirano as a member of the museum's board of governors.

"I'm not surprised she caught his eye. She's extremely capable and quite outstanding in terms of her personal capabilities and the leadership she provides."

A SURPRISE FOR MANY

Nonetheless, their engagement was surprising, Matsumoto said.

"The news took a lot of people by surprise," he said.

One of those was Akemi Kurokawa, president of Hawaii Prince Hotel Waikiki and Maunakea Resort on the Big Island. Kurokawa also serves on the board of governors of the museum, and calls Hirano "a brilliant leader" and "a terrific person."

But he completely missed the budding romance.

"I didn't realize they are in that kind of relationship," he said, "but my wife told me she knew it was going to come. ... That was probably women's intuition."

The issue of his surprise engagement has not been lost on the senator.

"I can imagine what's going through the minds of some of my buddies," he said wryly after the 65th anniversary luncheon last Sunday that brought together hundreds of his wartime compatriots from the legendary 442nd Regimental Combat Team.

Again, his bride cast him a surprised look.

"They're thinking they're very happy for you," she said.

Kurokawa concurs with her.

"Both of them deserve congratulations," he said. "It's a good union for both of them. ... After he (Inouye) lost Maggie I think all the more he needed someone to really help him because he is such a busy person."

'I LIKED WHAT I SAW'

Inouye and Hirano have known each other over the two decades she has headed the Japanese-American National Museum. He has chaired the board of governors, and has been a staunch supporter and benefactor as the museum flourished under Hirano's leadership.

Inouye said that while he saw Hirano three or four times a year on official museum business, in the two years since his wife's death, he began to look at her differently.

"And I liked what I saw," he said. "So I proposed. And here we are."

When he told the story at a recent banquet in his honor, he added with a kind of wonderment, "I think she loves me."

The couple has not yet worked out how they will juggle their careers, but Hirano has resigned as CEO of the museum, although she remains as board president. The two are still working out how to synchronize schedules, dividing time among residences in Washington, D.C., Los Angeles and Honolulu, and also their two adult children.

Hirano's daughter, Jennifer, is a graduate of Tufts University and is now studying for her MBA in New York. Inouye's son is married and has a career in music promotion.

While Inouye and Hirano are 24 years apart in age, they share a passion for bringing diverse people together and bridging cultural divisions. For Hirano, some of that has come from her family's history, some from her own experience of racial misunderstanding in America.

"The most common experience (of Japanese-Americans) is that people believe we are foreigners," Hirano said. "I have been told, 'Your English is very good, where are you from?' "

In the aftermath of the Sept. 11 attack, under Hirano's leadership, the Japanese-American National Museum reached out to the Arab community in Michigan to help ease brewing racial tensions. Already the Los Angeles museum board had been working with the Dearborn, Mich., community as consultants for a similarly based Arab-American National Museum.

"We realized it was important as a Japanese-American institution to speak out about what happened to Japanese-Americans after Dec. 7th," Hirano said. "It was important that we make a public statement. ... It reassured people there were friends willing to speak out and stand by our colleagues there.

"The reason that the museum was created was to ensure that the past would not happen again. For many younger Japanese-Americans, they heard the stories of World War II, but they never believed that it could ever be a threat, that this could happen again."

'A LASTING IMPRESSION

Hirano comes from the generation that knew little about the history of World War II Japanese internment camps — and the impact on their own families — until the subject came up in college.

Only while researching a paper on the issue, did she discover that her own grandfather had been interned, with seven of his children, and his property confiscated. Only her grandfather's eldest son, Michael Yasutake, who would become Irene's father, escaped the camp experience because he was already serving with the U.S. Military Intelligence Service.

Her grandfather's family had been rounded up with thousands of other Japanese-Americans, and imprisoned in a camp in Rohwer, Ark., the same camp that seared a lasting impression on an 18-year-old Army volunteer named Daniel Inouye and the 442nd Regimental Combat Team.

A visit to that camp by the Hawai'i men training not far away at Camp Shelby, Miss. — and the sight of Japanese-Americans behind barbed-wire and machine gun towers — created a lasting bond between the Islanders and their Mainland counterparts.

"That hit us right between the eyes," said Inouye of the barbed-wire and gun towers. "It has always haunted me — would I have volunteered if I was in that camp. I don't know."

Hirano, too, had questions about why the families didn't protest. But she says she has come to see it was a very different time.

"Our parents did what they had to do," she said.

And when the U.S. govern-ment issued an official apology to the 120,000 internees in the late 1980s, it was far more meaningful than the monetary compensation, she said.

"For most of the people I have talked to, that was the most significant part of the act," Hirano said. "The fact the U.S. government apologized. ... It has never done that before."

SHARED ROOTS

The search for an understanding of cultural roots, and their meaning today, has become a dominant theme in Hirano's life, not just for herself, but for the third, fourth, fifth and sixth generations of Japanese-Americans whose cultural past was indelibly altered by the World War II experience.

"The experience of my own family helped inspire me to join the Japanese-American National Museum," she said. "And as part of that work I began to realize a lot of the younger generations knew very little about their family in Japan. So that has led to a lot of work to strengthen and help people connect."

To that end, she and Inouye have discovered they share ancestral roots from the southern Japanese prefecture of Fukuoka. On a recent trip to Japan heading a delegation of Japanese-American political and business leaders from across the U.S., Hirano made it a point to locate a map of Fukuoka and look up the places where both their families come from.

"In thinking about identity and pride in one's culture," she said, "it's a shame not to go back and search for one's roots."

CULTURAL REAWAKENING

Hirano's efforts to rebuild intellectual, academic, cultural and friendship connections between the two countries are bearing other fruit.

For Hawai'i attorney Robert "Bobby" Ichikawa, who was invited to join one of the most recent cultural leadership exchanges led by Hirano, the experience rekindled a desire to more deeply explore his heritage, and pass that on to his sons.

But it also encouraged him to be more proactive to benefit the next generation. Recently he led his own trip to Japan with a baseball team of 11- and 12-year-old Hawai'i boys and their families.

"Because of World War II, Japanese-Americans severed their ties with Japan to show their patriotism," he said. "Now we're trying to reconnect. There's a lot of culture we don't know but want to learn."

Ichikawa said he owes this reawakening to Hirano.

"She has done so much for moving the Japan-American relationship forward. I think it's an important vision for her and I think the senator has the same vision. It's the senator's position that it's very important to have this strong relationship between Japan and the U.S. He always saw Japan as a key ally."

As Hirano and Inouye put together the final plans for their wedding, and ponder hosting receptions, they are also setting the stage to begin new joint projects, especially some based in D.C.

And when it comes time for the next election — Inouye has already announced he'll run again — Irene will be in the trenches, step by step, stumping at his side.

"That's one of the conditions," he jokes.