I picked up an used usuba from eBay and am curious to know more about it. Seller listed the kanji as Sadamune which doesn’t have much information on this forum or elsewhere. I’m in the process of refinishing this knife and I’ve been wholly impressed.
Link is here: https://www.ebay.com/itm/2047317600...0oqpuEoT-y&var=&widget_ver=artemis&media=COPY
Link is here: https://www.ebay.com/itm/2047317600...0oqpuEoT-y&var=&widget_ver=artemis&media=COPY