A delegation from Honolulu -- made up of representatives from the city, tourism industry, and business owners -- recently traveled to Nagaoka, Japan to discuss possible partnerships between the two cities.
It's all part of an effort to strengthen the bond between the sister cities, which share a very complicated history that began in World War II.
Nagaoka is in the Niigata Prefecture -- about 170 miles northwest of Tokyo. The city is known for being the birthplace of Admiral Isoroku Yamamoto, the Japanese Naval Commander who reluctantly orchestrated the surprise attack on Pearl Harbor in 1941.
"He was ordered to fight the United States as the top official of the Japanese Imperial Navy," said Takashi Hoshi, of the Admiral Isoroku Yamamoto Memorial Museum.
Hoshi says Admiral Yamamoto strongly opposed going to war with the U.S., but led the massive air strike on Pearl Harbor out of loyalty to his country.
In 1943, he was killed when American forces shot down his plane over Bougainville Island.
Then during the final weeks of World War II, on the evening of Aug. 1, 1945, the U.S. dropped firebombs on Nagaoka for close to two hours, killing almost 1,500 people and destroying 80 percent of the city.
"The entire downtown area was destroyed. Only the reinforced concrete buildings remained, but other buildings and houses were all destroyed and burned down," said Hoshi.
Having both experienced the pain of war, Nagaoka and Honolulu have been working to strengthen their bond.
In 2012, the sister city relationship became official.
"I believe Nagaoka and Honolulu paved the path of reconciliation for our countries," said Nagaoka Mayor Tatsunobu Isoda.
The cities currently share educational and cultural exchange programs for students. Nagaoka also supports Hawaii events, such as the Honolulu Festival, by donating its world class fireworks to organizers.
"For more than five years, they have consecutively had a chance to have a fireworks show in Waikiki Beach. That's magnificent," said Tsukasa Harufuku, president of the Honolulu Festival Foundation.