Harry Kilmer, a retired detective from Los Angeles, is called to Japan by his friend George Tanner who needs his help in finding his daughter, who has been kidnapped by the Yakuza. Harry has a personal connection to Japan and its culture, having served as a soldier during the American occupation of Japan after World War II.
Upon his arrival, Harry discovers that the Yakuza are not to be trifled with, and he seeks the help of his former army buddy Ken Tanaka, who is now a high-ranking member of the Yakuza. Together, they delve further into the underground world of the Japanese mafia in order to find George's daughter.
As they get deeper into the investigation, Harry uncovers secrets from his own past and a long-buried love affair with Eiko, a Japanese woman who is now married to a powerful Yakuza boss. This complicated personal history puts Harry at odds with the Yakuza and complicates his mission to rescue George's daughter.
Amidst a backdrop of cultural clashes and intense violence, Harry and Ken navigate their way through the underworld of the Yakuza to find the path to George's daughter and bring her back alive. The Yakuza is a tense and emotionally charged thriller that explores the intersection of two vastly different cultures, and the price of loyalty and honor in the face of danger.