The leader of the Yamai Syndicate, a gang based in Honolulu City, Hawaii, appearing in Like a Dragon 8. Born August 19, 1973. Blood type O. Formerly a member of the Tabata Family, a direct subsidiary of the Tojo Clan. About 30 years before the main story, he fell in love with the patriarch's wife. Ultimately, he took the blame for murdering his own patriarch and was expelled from the clan. After fleeing the country, he drifted to Hawaii. He is so sensitive to the cold that he wears a heavy coat even in tropical Hawaii, and he uses a crowbar in combat. He is always calm and composed, though he lets his guard down around the hostesses and members of his own territory. Furthermore, he holds a deep admiration for Kazuma Kiryu, who was once a legendary figure in the yakuza world, and displays a tremendous obsession with him up to a certain point. He refers to Kiryu as "Kiryu-san." His first impression is poor due to his treatment of his subordinate, Eric Tomizawa, but contrary to this outward personality, he is well-regarded by his organization and the local community. When Tomizawa tried to attack him, the hostesses (who seem to be older women, suggesting his preference) shielded him, saying they wouldn't forgive anyone who touched Yamai. When he tried to leave Hawaii, his subordinates tearfully saw him off, shouting that they would wait for their "Patriarch" to return. He possesses a charismatic side, responding with "Don't die until I get back," revealing glimpses of a good-natured man hidden beneath the surface. However, he is the type to put his full effort into harassing those he dislikes, regardless of profit or past grievances, showing a rather nasty side to his personality. Also, since he is technically no longer a yakuza, his group is the "Yamai Syndicate" rather than a "Family," but his members call him "Patriarch" and refer to themselves as "clan members" of their own accord. Initially, he corrected them every time, but since they never stopped calling him Patriarch, he eventually found it too bothersome and has recently left them to it. During his time in the Tabata Family, he was in love with the patriarch's wife, Yui Tabata, but she was also having secret meetings with the captain. At one point, to hide her relationship with the captain, Yui asked Yamai to kill her husband, the patriarch, and make it look like self-defense. Yamai accepted the request, harboring a faint hope that it might win her affection. Things went according to plan, but immediately after the murder, Yui betrayed him, claiming he had killed the patriarch and then tried to attack her, forcing Yamai to flee. While attempting to escape, he became worried about Yui and went to check on her in secret, only to be disheartened by the sight of her being intimate with the captain in public. This incident caused him to suffer from uncontrollable "chills" (the reason he wears a coat at all times). He subsequently fled to Hawaii to escape the Tabata Family and the police, where he formed the Yamai Syndicate with local Japanese-Americans.

Originally an honest taxi driver with a pregnant girlfriend named Mary. However, Dwight Mendez, the leader of the Barracudas, framed the innocent Tomizawa for a crime they committed. The Barracudas had ties to the local police and judiciary, leaving Tomizawa helpless; he accepted the false charges and was sentenced to five years in prison. As a result, Mary suffered a miscarriage due to the stress and disappeared after visiting him once. He does not resent Mary for vanishing, instead saying it was his fault for putting her through so much hardship. However, he harbored a deep-seated hatred for the Barracudas, who ruined his life and, above all, killed his unborn child and made Mary miserable. He went as far as obtaining a gun to seek revenge and found Dwight, but he let his guard down. Despite reaching a point where he could have surely killed him at the cost of his own life, he lost his nerve at the last second, leading him to become completely cynical and delinquent. His debt was held by the Yamai Syndicate, and he has since been acting as one of Yamai's henchmen.