Akira Nishikiyama is Kiryu's sworn brother. He grew up in the "Sunflower" orphanage. Belonging to the Dojima Family along with Kiryu, he is active as a hot-blooded young yakuza. He supported Kiryu at the risk of his own life to raise money for his younger sister's surgery for a serious illness; to him, Kiryu was more than a real brother. He is Kiryu's irreplaceable best friend.

Kazuma Kiryu is the protagonist of the "Yakuza" series. With a "Rising Dragon" tattoo on his back, he is a legendary yakuza feared as the "Dragon of Dojima". He possesses a strong conviction to "help the weak and crush the strong", overwhelming strength, and a chivalrous spirit loved by all. Raised in the "Sunflower" orphanage, he met his lifelong friend Nishikiyama there. Later, he stepped into the yakuza world and rose to prominence in the Dojima Family, a direct subsidiary of the Tojo Clan.

Reina is the woman who serves as the Mama of the high-end club "Serena" on Tenkaichi Street in Kamurocho, Tokyo. She has been an old acquaintance of Kiryu and Nishikiyama since they were young members of the Dojima Family, and continues to provide them with one of their few relaxing havens.

Shintaro Kazama is the Patriarch of the Kazama Family and the foster father of Kiryu and Nishikiyama. Once feared as a master hitman, he is a man of deep compassion who values honor and is admired by many yakuza as a "man among men".

Osamu Kashiwagi was a master yakuza feared in Kamurocho as the Captain of the Kazama Family and Kazama's right-hand man. Always calm and loyal, he watched over Kiryu and Nishikiyama as an older brother figure and continued to support the organization.

Goro Majima is a super-militant yakuza feared as the "Mad Dog of Shimano", yet he lives a life deeply rooted in duty and humanity, faithful to his own aesthetics. Majima is extremely loyal, quick-witted, and has a cunning side. Calling Kiryu "Kiryu-chan", he recognizes him as a lifelong rival while also standing by him as his greatest supporter who occasionally saves him from predicaments.

Futoshi Shimano is the Patriarch of the Shimano Family. A big-time yakuza known for his massive frame and brutality, earning him the nickname "Tiger-Man". He was also Majima's mentor in the yakuza world and the one who triggered the birth of the "Mad Dog of Shimano".

Sohei Dojima is the Patriarch of the Dojima Family. He is the mentor of Kiryu and Nishikiyama in the yakuza world, a yakuza with ruthless brutality and greedy ambition.

Ryuji Goda is the Chairman of the Go-Ryu Clan, a direct subsidiary of the Omi Alliance. People call him the "Dragon of Kansai". Boasting overwhelming popularity as one of Kazuma Kiryu's greatest rivals, he is a boisterous yet honorable yakuza.

Nishida is a junior member of the Majima Family. While he is a hard worker constantly jerked around by the unpredictable actions of Patriarch Goro Majima, he is known as a precious man of common sense who admires him more than anyone.