The Saio Triad was a Chinese triad organization which operated in mainland China and Japan. The triad was known for its "blood law", requiring all of its leaders to be blood relatives in order to prevent factional struggles and intra-family conflict. The triad worked with Yomei Alliance boss Heizo Iwami to smuggle Chinese workers to Japan near the end of World War II to serve as cheap labor in the Imperial Japanese Navy's shipyards. In 1986, Big Lo became the triad's new boss, and Lo worked with the Yomei Alliance to obtain citizenship papers for heihaizi, undocumented Chinese children born in violation of China's "one-child policy". In 2015, Jimmy Lo led the group's expansion into the Japanese underworld against his father's advice, and Tsuneo Iwami attempted to use the group to aid him in overthrowing his father and install Katsumi Sugai as acting chair of the Tojo-kai. Once Sugai was installed, Jimmy Lo attempted to double-cross the Saio Triad, hiring the Jingweon Mafia to kill Big Lo and Jimmy Lo. Only Jimmy Lo was killed, and his father Big Lo sought vengeance. Lo's second son and backup heir, Yuta Usami, attempted to kill his father after discovering his true parentage, as he had been raised without the knowledge that his father was Chinese, and he was only brought to Japan to fulfill the "blood law" should Jimmy Lo die, in which case he would be informed about his true identity and asked to step up. Kazuma Kiryu prevented Yuta from killing his father, and Big Lo - now without an heir (his elder son was dead, and his second son hated him) - decided to abdicate as the triad's leader and allow the other officers to select a new leader, ending his family's control of the triad, and making it likely that the new boss would have him killed to prevent him from returning to power. The Saio officers in mainland China proceeded to recall the triad's members back to China, ending its operations abroad.