When Hiromi Peterson and Naomi Hirano-Omizo began writing their “Adventures in Japanese” textbooks nearly 30 years ago, they had only their Punahou School students in mind.

Today those engaging volumes are the best-selling Japanese-language textbooks in high schools across the United States. And they have created a legacy of their own. The co-authors have been quietly using their royalties from the book series — $1.6 million to date — to build bridges of understanding.

On today’s anniversary of the U.S. atomic bombing of Hiroshima, students from Hawaii and Japan are gathering at the Peace Memorial Park in Hiroshima for a ceremony of remembrance and to forge links for the next generation. Their trip was funded by those royalties.

The two longtime Punahou teachers hail from disparate settings but have become so close that they finish each other’s sentences. Peterson was born in Hiroshima three years after the nuclear bomb devastated her hometown. Hirano-Omizo grew up on Hawaii island, the granddaughter of a Japanese immigrant who was interned during World War II.

Peterson moved to Hawaii in 1972 when she married her American husband, and has listened to the stories of the survivors of the devastating attacks on both sides of the Pacific.

“I hear the same words from both Pearl Harbor victims and Hiroshima victims: ‘I just don’t want the same thing to happen to anyone else,’” she said. “If we pass our message to the young people, I hope the seeds of peace will come up, here and there. At least it’s better than doing nothing.”

The pair have donated their royalties to Punahou since their first volume was published in 1998, money that has funded student travel scholarships and training for foreign-language teachers. It also pays for the Hiroshima Peace Scholars, their special project that is marking its 10th anniversary this year. Peterson retired in 2014, but they continue to update their multilevel curriculum, which includes texts, workbooks and audio and is published by Cheng & Tsui of Boston.

Each year, two Punahou students are chosen as peace scholars and travel with a teacher to a sister school in Hiroshima to commemorate the anniversary of the attack and to work with other students to promote peace. This year, for the first time, two public school students were selected to join them.

Punahou seniors Eden Chun and Megan Kobayashi and Farrington High School seniors Beigie Lam and Elarie Ranido are visiting Jogakuin High School, which is near the epicenter of the bombing. It lost 350 students and teachers in the attack.

The school holds a memorial followed by a peace forum every August that draws students from across Japan. The Hawaii students also tour the Hiroshima Peace Museum and Peace Memorial Park and speak with survivors. They stay with Japanese families and take a field trip to Miyajima.

“This is a really good way to not forget about what happened, to come to an understanding and be able to move forward instead of having history repeat itself,” Chun said before leaving Tuesday for their 10-day trip to Japan.

The scholars came up with their own projects to promote peace. Megan, who mentors students on a robotics team at the Hawaii School for the Deaf and the Blind, staged activities for hearing students that simulate being deaf to raise their awareness and openness. Chun asked students at Punahou and Farrington to ponder what peace means to them.

“I asked them to visualize it and draw it onto pieces of fabric, which I then took and sewed all together to make a patchwork quilt of peace,” she said. The quilt was their gift to Jogakuin School. She also brought fabric squares with her to Hiroshima so her Japanese colleagues could illustrate them with their visions of peace.

The Hawaii scholars also brought a “senbazuru,” a garland made up of 1,000 folded paper cranes, to present as a symbol of peace at Hiroshima Peace Memorial Park.

Peterson’s family was shattered by the atomic attack 73 years ago, but her parents survived and were interviewed by the Hiroshima Peace Museum about their experiences, a video that the Hawaii students watch when they visit.

“My grandfather died after one week,” she said. “My mother and my older sister died later from leukemia, not immediately, from radiation. All my family is affected by the atomic bomb experience.”

Hirano-Omizo wasn’t born until 1953, but her grandfather, who immigrated from Shizuoka to Hawaii and lived outside Volcano, a farmer and Japanese teacher, was arrested after Japan bombed Pearl Harbor on Dec. 7, 1941, and spent its duration in various internment camps on the mainland.

“I was 9 when he passed away,” she said. “I think the message of that story is his inner strength, how he was able to come out of that still strong and amazingly not very bitter at all.”

Each month, Punahou students go to the Arizona Memorial at Pearl Harbor to teach visitors how to fold origami cranes. The memorial also receives thousands of origami cranes in the mail and gives them individually to visitors from around the world.

“When you travel, you put a face on a person,” said Lam, one of the Farrington students. “It’s much harder to attack someone when you can put a face on them.”

“I feel like world peace is such a big concept,” she said. “If you start with one person at a time, then when your future arrives, when you are that future, you can make it happen.”