Tales of Tolgard
For most of recorded history, Mt. Fuego has been a bone of contention in Keshiki. Several clans of fire giants have always called the lava tubes and caves beneath the peak home. Understandably, there have been numerous clashes over the years between samurai guards and giant raiding parties.
A few centuries back a wise daimyō decided to try a trade solution since military action did not seem to be working. Without the expertise of dwarves, who were virtually unknown in Keshiki, there was very little high quality steel being produced. Recognizing the potential of the giants fiery home, the daimyō opened negotiations.
It was a long and arduous process. There was much distrust and centuries of killing on both sides to overcome. Still, eventually a trade agreement was reached. In exchange for advanced knowledge of smelting steel and a steady supply of iron bars, the giants would smelt the alloy for the Keshikans. For a low price, since they were providing the materials, the giants would sell the Keshikans all the steel they wanted.
This flow of steel, limited only by the iron mines production, has helped equip and protect the entire nation. In fact, so much surplus is produced by the agreement that keshiki steel is traded around the world.