OK - I'd say it's an Edo era artifact that has been badly abused. Maybe a small boy's day sword, maybe a part of a sword that was repurposed as a tantō...hard to say. But its lost its shape due to wear and maybe due to an amateur polishing. Someone has aggressively polished the tang, which has removed all patina from it, so its a big negative factor in evaluating the blade.
The name on the tsuba looks like 忠重 (Tadashige). I don't have any info on him off the top of my head. But the koshirae fittings (including the tsuba) were most likely assembled well after the sword was made.
Sorry I can't be of much more help, but any identifying features have been lost due to some rough treatment.