Honolulu Mayor Jeremy Harris, left, with Uwajima Mayor Hirohisa Ishibashi, said "no sister-city relationship will be stronger ... than this one." Andrew Shimabuku • The Honolulu Advertiser

Honolulu Mayor Jeremy Harris said the cities had formed a unique bond as they grieved together.

"Sometimes in history, out of tragedy comes a spark of goodness," Harris said during a ceremony yesterday at City Hall.

Uwajima Mayor Hirohisa Ishibashi thanked Honolulu residents for the kindness and aloha they extended after the accident, and said he hoped the cities would enjoy a long-lasting friendship.

The ceremony included performances by the Royal Hawaiian Band and Halau Hula Olana.

Ishibashi said Uwajima has three sister cities in Japan, but that Honolulu had become the first outside the country to receive the designation.

Uwajima is Honolulu's 23rd sister city. Harris said the circumstances that led to the arrangement with Uwajima make the ties special.

"No sister-city relationship will be stronger or more heartfelt than this one," he said.

Honolulu is among the U.S. cities with the most sister-city agreements. Los Angeles has 20, Seattle has 21, and and Chicago also has 23. Hawai'i last year signed a similar agreement with Japan's Ehime prefecture, which includes Uwajima.