A Son of the Good Earth

Chinese orphan Riku Isshin is suspected of being a Japanese special spy and sent to a labor reformatory during the Cultural Revolution. Seven-year-old Matsumoto Katsuo (Riku Isshin) has lost his grandfather and mother, and is separated from his younger sister Atsuko. He was rescued by an elementary school teacher, Riku Tokushi, who raised him as his son. Meanwhile, Matsumoto's Japanese father, Koji Matsumoto, was demobilized and worked at a steel mill while waiting for his family, and later lost his wife, whom he remarried.

Riku Isshin cannot forgive Matsumoto Koji and suffers from the fact that the person in charge of the Japanese side is his own father. As the construction of the steel plant comes to an end, Isshin comes back to Japan to inspect the power distribution equipment. He visits Koji's house, violating the rule that prohibits him from going out alone without permission. Father was living alone and lonely in a small company housing. He showed a picture of his mother and his sisters' Buddhist mortuary tablet, and Isshin felt a sense of "family" that is no longer there. However, while out of the house, Isshin's confidential documents are stolen.

Riku Isshin grew up to be a brilliant young man. However, when the Cultural Revolution began in 1966, he was falsely accused of being a Japanese spy. He was sent to a labor reformatory, where he was forced to work hard at dam construction and other hard labor. For solace in such a life, he had memories of his best friend Yuan Rikibon and his college sweetheart Tan Qing, and in August 1970, his biological father Koji Matsumoto, now in Japan, attended a memorial service for the Manchurian Settler Communities in his hometown of Nagano and heard stories about the search for his relatives who had remained in Japan after the Chinese occupation.

A few years later, Lu Isshin was sent further into the countryside to work as a shepherd in the Inner Mongolia Autonomous Region. On the grassland, he met Huang Shouhai, an overseas Chinese returnee from Japan, and learned Japanese. He also met Jiang Yue Mei, a nurse in the traveling medical corps who nursed Isshin through the night after he contracted tetanus. Hearing Isshin's wish to tell his adoptive parents about his situation, Jiangwolmei wrote a letter to Lu Dezhi. Upon learning of his son's false accusation, his adoptive father went to Beijing to help his son.

Riku Isshin is reunited with Jiang Wolmei during a sandstorm, but despite his mind, he rejects Wolmei's love. Meanwhile, his adoptive father, Riku Tokushi, is struggling for Isshin. It was Isshin's close friend, Yuan Likibon, who stepped forward at that time. Thanks to the efforts of Yuan Lik-bon, who worked in the military, Isshin was suddenly released in May 1972. In September of the same year, the Sino-Japanese joint statement was reported, and Isshin returned to the Steel Company, where he became a librarian and married Wolmei the following spring.

In 1977, a delegation from the Chinese Institute of Metallurgy visited Japan, and a state-of-the-art steel plant was awarded to Toyo Seitetsu. Riku Isshin was assigned to work as a member of the Japan-China joint steel plant construction team, and Toyo Seitetsu in Japan sent Matsumoto Koji, Isshin's father. Isshin and Koji were to be involved in the same project, with both the company and the country on their shoulders. Koji and Isshin meet his adoptive father, Lu Dezhi, in Beijing when he comes to Beijing about a story of a Japanese orphan who is searching for his immediate family, and they meet on the Great Wall of China, unaware that Koji and Isshin are adoptive father and biological father and son.

Koji Matsumoto is still searching for his wife and children who disappeared in Manchuria (northeastern China). 1978, Koji returns to Japan and hears that Katsuo (Riku Isshin) and Atsuko, the children he left in China, are still alive. Meanwhile, Riku Isshin was ordered to go to Japan on a business trip and visited Hakone for the first time, where he heard Kiso-bushi (traditional Japanese folk music) and saw Mt. Koji participates in a search for orphans in China and meets a farm woman who remembers Katsuo and Atsuko.

At that time, Jiang Wenmei examined Zhang Yuhua, an orphan who was believed to be Atsuko, the younger sister of her husband Lu Isshin, in a farming village near Beijing. Told by Wolmei that her life was in danger and that she should see her as soon as possible, Isshin hurried to the woman. After 35 years, the brother and sister are reunited, and thanks to Tsukimai's efforts, Atsuko is admitted to the hospital. Isshin visits her and teaches her Japanese as requested, but Atsuko's condition suddenly changes.

Matsumoto Koji finds the whereabouts of his daughter Atsuko. However, when he arrives in the village, he finds that Riku Isshin has already taken care of Atsuko. Isshin and Koji are surprised, but understand that they are father and son. It was a reunion of father and son, and a farewell to their daughter. Koji visits Isshin's adoptive father, Riku Tokushi. His aging adoptive parents are heartbroken, wondering if they will be asked to return Isshin. Meanwhile, since his first visit to Japan, there have been a series of tip-offs about Isshin.

Riku Isshin is accused of losing confidential documents in Japan and is transferred to the Inner Mongolia Autonomous Region. His father, Koji Matsumoto, asks the company for his resignation as head of the Shanghai office in order to clear his son's false accusation, but his request is not granted. Isshin is saved by his former lover, Tanqing. When she learned that her husband had wronged Isshin, she was prepared to divorce him and reveal the truth.

After being cleared of all charges, Riku Isshin returned to the steel plant construction site and worked hard. In November 1985, the completed steel blast furnace was lit. Father and son embrace. After the project was completed, Matsumoto Koji and Isshin set off on a trip down the Yangtze River. On the boat, Koji asked Isshin if he could come back to Japan. Isshin tells him that "I am a child of the earth" and that he is determined to stay in China.