Into Tatsu
Whatever the causes or occurrence, every age of humanity in Kudao reaches the industrial age eventually. In this timeline, it seems the islanders of Tekkan seized it first. The Seigun Shogunate once governed the island with traditional values for over a thousand years. But as time went on, lesser clan leaders such as the jitō of clan Tatsu in the central quarries, discovered new ways of advancing humanity while the Seigun samurai remained blinded by the old ways.
Over the next few centuries, clan Tatsu's political power quickly grew with the resources found within their own mines. Allowing them to evolve past their once higher-ups, even larger than the Seigun Shogunate. After a certain world-changing event, the people of Tekkan came to realize that their country was safer in the hands of clan Tatsu, forcing the Seigun Shogunate to disband.
The new Tatsu Shogunate pushed the modernization of their country even further with their new government control. Mines produced more efficiently, cities became taller, and the skies turned grey from the escaped fumes. Tradition was fleeting, but perhaps it was meant to be.
The Tatsu Capitol.
The same place, 180 years ago.