Help reading a five-character mei?

[SteveC]

Hi all, first post. Katana in shirasaya, and I'd like help reading the tang. Not after a valuation - I just want to know what it says.

The inscription is on one face only. The reverse is completely blank apart from the mekugi-ana (photo included), so there's no date anywhere on the blade.

My best guess is a five-character mei ending in 國貞. But I honestly can't tell what the FIRST character is, the one nearest the machi. It reads to me as either 大 or 文, and that changes everything.

I did look before posting. I know the well-documented Kunisada is 和泉守国貞, Izumi-no-kami, founder of the Osaka Shinto school - and that's a different title from what I think I'm seeing. I've been through nihontoclub, touken-world, meitou.info and this board in both English and Japanese, and I can't find a Yamato-no-kami Kunisada anywhere.

So just two questions:

1. What do you read?
2. Is that first character 大 or 文?

Blade is ubu, one mekugi-ana, nagasa 65.2 cm, unpolished, shirasaya.

Photos are CLAHE-enhanced to lift the chisel strokes; an unprocessed colour version is included too. I have 124 raw frames of this tang at full resolution, so if a different angle or lighting would help, just say and I'll pull it.

Thanks for any reading, including "you've got it wrong."

 

Edited August 24 by SteveC

[Ray Singer]

The kanji and reading are below:

 

大和守国貞 - Yamato (no) kami Kunisada. 

[SteveC]

Thank you very much!! That settles the character I couldn't read, and it confirms the name.

Two follow-ups if you have a moment:

1. Since there's no date on the blade, is there anything in the sugata that suggests a period to you? I had been assuming Bunsei, but I now realise that assumption rested entirely on my misreading 大 as 文, so I have nothing behind it.
2. Is 大和守国貞 a name you've encountered before? I can't find a Yamato-no-kami Kunisada in any reference I have access to - only the Izumi-no-kami line. I'm not looking for a valuation, I just want to understand whether this is a smith who's simply outside the indexed record or whether I'm missing something.

Happy to shoot better photos of the blade if it would help - the one I posted has the kissaki out of frame.

Thanks again.