Japan did, but not in the conventional sense. Japanese metalworkers could produce steel, but they did this using iron sand and charcoal in a long-burn tub furnace called a tatara. The tatara produces (it's still used today) a giant blob of mixed ferro-carbon compounds at the bottom which contains iron, unburnt carbon, various impurities, and a small amount of steel. The best of that steel is called tamahagane and is used to produce the cutting edge of bladed weapons. This is why katanas have an iron body and just a bit of steel edge. The tatara simply can't make enough steel to allow for fully-steel blades.
Japanese industrial base in the Sengoku era was very badly lacking in its ability to perform high-temperature metallurgy needed to produce large amounts of steel consistently because of several factors. The most important one is that unlike China Japan had no major coal resources (China was and still is one of the world's largest coal producers). The Japanese archipelago simply didn't have the fuel type needed to run large high temperature furnaces. That's why uncle "invented" biocoke. Coke is a form of processed coal (made using anaerobic distillation) that can generate much higher temperatures when burned than coal straight from the ground. Biocoke is imitation coke made from organic matter (biomass). I was kinda amused reading through the comments because everyone was complaining about the Sharps rifle being way too ahead of its time. Biocoke is a TWENTY-FIRST CENTURY INVENTION. Well, okay, it was first synthesized in the 1960s, but the process to make it viable only came around in Japan in 2005.
If you ever have a chance to visit Japan and want to look at a tatara blob in real life, you actually can. The Japanese Sword Museum has one on permanent display right in front of the entrance. It is located at 1-12-9,Yokoami, Sumidaku, Tokyo 130-0015. Very nice place. Highly recommended. I try to go there every time I visit Tokyo.
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