Reddit reviews The New Generation of Japanese Swordsmiths

Haha, I wish! I could tell it was nihontō from the photo, with true hōnoki shirasaya (the "tiger striping" is very distinctive) and what was at least a gold-foiled habaki. At best, I guessed that it might be shinsakutō, but that's really the limit of my analytical powers. I did a reverse image search to find the sale page (which I linked to in the line "sold for $4500"—maybe I should have made that more obvious?), which is where the other details came from. Er, and I already knew a little about Sadahito since I've researched his family specifically before; he's featured in The New Generation of Japanese Swordsmiths.

Had I seen the full-res workmanship closeup, I'd have been able to tell you it is Sōshū-den, with ji-nie, abundant sunagashi & nijūba, etc. And I would have been more confident that it is shinsaku. But I still wouldn't have assumed it was by Enomoto Sadahito. That only came as a pleasant surprise, when I saw the description.

—G