After three years serving as a U.S. Army military policeman in post-war Tokyo, Sgt. Robert Douglas considers himself very knowledgeable about the Japanese people and culture. His tour of duty over, he is preparing to return to America soon with his girl friend, singer Sumi Fujita. At the Ginza, the nightclub where Sumi performs, Robert draws the ire of manager Nakamura when he reprimands the establishment for allowing American G.I.s to drink and fraternize with B-girls. American reporter Jesse Bronson chastises the sergeant for his by-the-book approach to law and order, but Robert, who believes that all army rules must be strictly adhered to, ignores him. That night, he visits a gift shop to purchase a new fan for Sumi, and there takes pride in proving to the salesman that he is no ordinary foreign tourist, but knows the history and significance of the various items. Outside, two boys are ransacking his car, and when Robert struggles with one, his gun goes off, shooting the other. Although his superior officer, Maj. Bradley, believes that Robert was innocent of wrongdoing, he reprimands him for drawing his gun, as the incident will add heat to the already touchy diplomatic relationship between Japan and the American military, which is in the country on what he calls a "goodwill mission." At dinner that night, Sumi distracts Robert from his distress, but they learn later that the boy has died of the gunshot wound. When Bradley announces to the press that Robert will stand a court-martial, the Japanese reporters remind him that, according to the latest treaty, their country has the right to try Robert in Japanese courts. Robert, who believes that the United States government will protect him by refusing to turn him over to the Japanese, asks Sumi to bring him to the parents of the dead boy, so he can apologize. There, the father, who is performing a mourning ceremony, responds with anger, especially after Robert offers money to pay for the funeral. Outside, protesters throw rocks at Robert, calling him a "dirty American killer." Even at Sumi's home, her brother lashes out, informing Robert that the older boy has asserted that Robert killed the younger boy without provocation. When Sumi asks Robert if any of the story is true, he storms out in a rage. Over the next few days, the crisis grows, with the Japanese public casting Robert as a typical imperialist brute, prompting demonstrations at the U.S. Embassy. While the army orders Robert confined to quarters, Bronson begins a public-interest campaign in the American papers blaming the government for failing to exonerate an innocent man. The reporter then visits Robert's quarters, where he reveals that Robert will soon be handed over to the Japanese and urges him to hire a civilian lawyer. Robert insists that the army will take care of him, and knowing that Bronson's first priority is to land a good story, brushes him off. When an MP arrives to transport him to the Japanese military camp, however, Robert heeds Bronson's words, knocks out the guard and flees into the city. Sumi, whose visits Robert has refused, visits Bradley to ask for help, and there learns that Robert has escaped. Seeing that Sumi blames herself for causing Robert to lose faith in the Japanese people, Bradley soon convinces her to call him if Robert contacts her. Guessing correctly that Robert will head to the older boy to ask him to change his story, Sumi finds the fugitive there and, after Robert embraces Sumi gratefully, offers to hide him at the house of her blind sensei, or teacher. Soon after, the U.S. ambassador warns the army that locating Robert is of paramount importance to future relations between Japan and America. At the Ginza, Sumi informs Bradley that she will not turn Robert in, but agrees to arrange a meeting at a temple the next night. Bronson overhears them and follows Sumi back to the sensei's house, where he urges Robert to let him smuggle him to San Francisco and there rally American support for his release. Distrusting, Robert tells Bronson he will soon decide, then agrees, for Sumi's sake, to talk to Bradley. At the temple, Bradley asserts that Robert will receive as fair a trial in the Japanese courts as in the American courts, and urges him to face the issue instead of running away. Robert refuses to turn himself in, however, and leaves knowing Bradley will be forced to hunt him down. Later, Bronson outlines the getaway plan, but this time states that Sumi will not be able to accompany Robert for some weeks. Despite Sumi's fear that she will never see him again, Robert believes he has no other choice. The three plan to meet the next night at the Ginza, where Bronson will lead Robert to a freighter that will transport him out of Japan. In the morning, Sumi promises Robert that even if they never meet again, she will always treasure their time together. When she leaves for work, the sensei explains the Japanese tea ceremony to Robert, who insists that he understands Japanese culture well. In response, the sensei points out that most of the Japanese people Robert has met do not even speak his language, and adds that much of the country's traditions take decades to comprehend. As Robert's discomfort grows, the sensei gently notes that although he expects Sumi to give up her home for his country's customs and justice, he will not do the same in return. Without comment, Robert leaves for the Ginza, where he kisses Sumi goodbye while Bronson waits impatiently. Perceiving her grief, Robert finally realizes that she wants him to stay and face the charges, and so sends Bronson away. Just before he surrenders, Robert praises Sumi for knowing what was right all along, and she replies that it was he who knew what to do.