Mizuguchi's 17-year-old son, Takeshi, was among the nine boys and men who died when a Navy submarine collided with their Japanese fishing vessel. Of the nine killed, Takeshi was the only one whose remains could not be found.
"Even though I cannot describe how the last 10 years have been to us, when I come here ... and see this magnificent ocean, it makes my heart calm," Mizuguchi said.
The nine were honored and remembered in a service Wednesday marking the 10-year anniversary of the tragedy.
About 20 family members bowed their heads and observed a moment of silence at 1:43 p.m. - the time when the USS Greeneville surfaced beneath and rammed the Ehime Maru on Feb. 9, 2001, off Oahu.
The 57-year-old Mizuguchi has visited Hawaii numerous times since the collision to mourn his son. He thanked volunteers who help maintain the memorial and the visitors who have paid their respect throughout the years.
"I believe that the nine spirits who rest here feel less lonely and are comforted by them," Mizuguchi said. "I am so grateful for all of you who help us heal our pain and grief with your warm support and love."
The solemn ceremony was attended by more than 200 people, including Ehime prefecture Gov. Tokihiro Nakamura, Hawaii Gov. Neil Abercrombie and Rear Adm. Kathleen Gregory of the U.S. Pacific Fleet.
They each laid wreaths in honor of the nine lost. In her Navy whites, Gregory saluted the memorial and bowed to the seated family members.
The service was held at the Ehime Maru Memorial on a balmy day at a palm tree-lined park near downtown Honolulu overlooking the sparkling Pacific and the urban Honolulu skyline.
A total of 35 students and instructors were onboard the vessel from Uwajima Fisheries High School when it was struck by the Greeneville about 13 miles outside Honolulu. Twenty-six people from the vessel were rescued from the oil-slicked waters. No injuries were reported on the 360-foot nuclear-powered sub.
"The incident shocked all of us immeasurably," said Hirohisa Ishibashi, mayor of Uwajima city. "The families of these nine lives, citizens of Uwajima city and the whole nation of Japan experienced great anger and sadness."
Wearing dark suits and dresses, relatives took the bright floral leis around their necks and hung them on the steel chain that surrounds the memorial. The monument is constructed of nine black granite blocks engraved with the outline of the ship; the Uwajima Fisheries High School emblem; the names, titles and ages of the victims; and a map showing the accident site and the ship's final resting place.
A one-ton anchor from the Ehime Maru rests atop the granite blocks. Next to the anchor were framed photos of the nine who perished.
The Navy's investigation concluded that the Greeneville's captain, Cmdr. Scott Waddle, rushed through mandatory safety procedures while demonstrating an emergency surfacing drill for the benefit of civilians touring the submarine. The sub's rudder sliced into the hull of the Ehime Maru.
The report said Waddle was in a hurry because he didn't want the submarine to be late returning to Pearl Harbor with the 16 guests. Waddle did not attend on Wednesday.
"If he were to come here, I wouldn't be here," Mizuguchi told reporters after the ceremony. "I would come to Hawaii but not here. I don't know about other families - that's up to them. That's my personal opinion."
The Navy and Waddle apologized following the highly publicized accident, although not as quickly as the victims' families wished. Waddle was reprimanded by a military court of inquiry but was allowed to retire with full rank and pension, which drew criticism in Japan that the punishment was too light.
"I'm fully aware there's a lot of pain and anguish, and I know from my perspective I'll never be able to get forgiveness from the Japanese families for the losses they suffered," Waddle said in an interview last week with The Honolulu Star-Advertiser.
Following the incident, Waddle wrote a book and became a consultant and speaker. He now lives in Cary, N.C. The families of the 35 victims agreed to a settlement with the Navy totaling $16.5 million.
Many of the cultural and legal differences between the two nations were highlighted in the wake of the tragedy. With widespread outrage in Japan, the Navy responded with unprecedented measures, including a $60 million effort to move the ship and recover the bodies.
Japan is one of the United States' most important allies and home to the U.S. 7th Fleet and the only American aircraft carrier permanently stationed abroad.
Edwin Hawkins, president of the Japan-America Society of Hawaii, said the ceremony was first to remember the nine and support their families.
"But also we are here to demonstrate to the world that tragic events between two great peoples cannot divide us, and that we can transcend the tragedy by dedicating ourselves to build lasting friendships through compassion and understanding," he said. "And in so doing, we honor the memory of those departed."