Yamato-san is an 80 year old elder statesman of Terminal Island, California. Having moved there as a fisherman, he now serves as a raconteur and honorary officer on the ship of fisherman Henry Nakayama. He is well-connected to the traditions of Japanese immigrants, considered important as the Japanese are sent to Japanese internment camps during World War II.
As a fisherman, he claims to have been named the "Tuna-Boxing Champion of San Pedro," having punched a 200 pound fish he caught himself in the face, despite having previously worked only as a tea farmer. He warns his fellow fishermen of there having been a Bakemono at the funeral of Masayo Furuya. ("A Sparrow in a Swallow’s Nest")
He was eventually released and sent to the Colinas de Oro War Relocation Center with the rest of his family. While his son, Henry, was badly traumatized both physically and mentally by his imprisonment and hard labor, he seemed to remain in relatively good spirits. ("Gaman")
He was present when Major Bowen and his men conducted a raid at the Colinas de Oro to search for contraband saké, blamed for MP Nessler's suicide. He explained that a woven basket was for the Japanese custom Obon to honor their ancestors, leading Bowen to tell his soldiers to sweep away all the "spook" stuff. He later joined the Nakayama and Yoshida families in praying over a memorial to Enrique and Hikaru Nakayama, the stillborn children of Luz Ojeda, his grandson Chester's girlfriend. ("The Weak Are Meat")
In February 1943, he and the other residents of the Colinas de Oro were given the Statement of United States Citizen of Japanese Ancestry, a loyalty questionnaire, to fill out. Upon being handed it, he expressed irritation that they would be required to prove such a thing, but the soldier who gave it to him, bored, told him to "Just fill it out, pal." He later visited Amy Yoshida, who was working as a secretary for Major Bowen, the chief of the camp. He told her that he needed to make a confession to Major Bowen, that he had once donated tinfoil for the Japanese Navy to make a solicitor to go away, and he didn't know how to explain it on the form. Amy warned him to say nothing about it. ("Shatter Like a Pearl")
Though not a onmyoji (specialist in magic and divination) himself, he knew something of old kaidan traditions. Thus, Chester turned to him upon learning that he was being stalked by the yurei of his birth mother, Yuko Tanabe. He sensed that Tanabe's spirit was away from her body and advised that he could banish her by destroying the body. Chester's adoptive mother, Asako, objected to this, but he said it was the only way and she eventually agreed. As part of the ceremony, he painted her entire body with Japanese characters, chanting Namu Amida Butsu, a Buddhist phrase. They then burned the body, but the spirit survived. ("Taizo")
He was released along with all of the others interned at the Colinas de Oro War Relocation Center after the United States Supreme Court ordered the closure of the internment camps in 1945. ("Come and Get Me")
He cried upon returning to Terminal Island only to discover that it had been reduced to nothing more than a field of dirt and fenced off by the U.S. government. One evening, he had a dream of vision, in which he walked along a lonely dirt road before encountering a man named Kazu, a childhood friend he had not seen for 75 years. Kazu told him that it was remarkable that they had been reunited in the afterlife. He spoke of how his father moved to Hiroshima, and he took a job with the railway there, where he worked for 50 years. He married there and had two children, three grandchildren and a great-grandchildren. Kazu's family then appeared before Yamato-san's eyes - they were all in the afterlife. As Kazu's great-granddaughter turned to show Yamato-san a badly scarred face, he awoke with a start.
He heard explosions and shouting outside. He and the others in the place he had found to stay went outside to discover a party atmosphere in the streets. He asked a man what was going on and was told that "we got 'em," that the United States had bombed Hiroshima and Japan would now have to surrender.
Later, he and Amy Yoshida sat outside talking. She was upset that people would be celebrating, noting that a child of Hiroshima wouldn't have anything to do with the war. She told him that she once wanted revenge, that it consumed her. She didn't feel any better when she got it. He told her in response that Major Bowen wanted to kill her and that it was either him or her. She was shocked that he knew, but he told her that it was okay, that only their own people knew. If the War Relocation Authority hadn't already figured it out, they weren't going to. He told her that it was easy to want vengeance, that it was natural. She asked about him, and he told her that he cried more tears seeing their home destroyed than he did the entire time they were interned.
Five years later, he was living in Hawaii with his great nephew, but came back to California for a family reunion. There, he met with an old friend named Genzo and traded stories. He told Genzo that everyone in Hawaii was Japanese, and Genzo told him that he and his family were taken in by people on a farm in Indiana, where no one is Japanese. Luz brought him a plate of treats, urging him to save some for the others. He commented "Oh my!" when she told him that she made them. ("Into the Afterlife")