After the war, numerous warlords and illegal organizations from various countries flew into Yokohama, waving extraterritoriality. In the blink of an eye, it became a city of lawless areas with violence and no peace. Natsume thereby brought Ōgai Mori and Yukichi Fukuzawa together to make the Tripartite Framework possible. After the plan came to fruition, Natsume retired.
The military police and Special Division for Unusual Powers headed by Santōka Taneda rule the day, the Port Mafia led by Mori rule the night, and the Armed Detective Agency led by Fukuzawa rule the evenings in between.
At some point, Mori intended to use Akiko Yosano's healing ability to revive his Immortal Regiment plan, which he believed would be beneficial in overthrowing the erstwhile mafia boss and therefore preserving Yokohama's peace for the sake of the Tripartite Framework. Fukuzawa and Ranpo Edogawa intervened Mori's plan, with Fukuzawa ending his alliance with Mori. In the end, the Tripartite Framework appears to have continued despite the two leaders' fallout.
At least a decade later, the plan almost collapsed once more when Mori and Fukuzawa fought each other during the events of cannibalism, stating that the strife would come down to an end if Fukuzawa dies, however the conflict would continue if Mori dies. Natsume's appearance and mediation eventually stopped their dispute.