The 7 characters running the center of the blade read
Yama-Shita-Kana-Mono-Ten-Toku-Sen.
Which translates as Yamashita Metalworks (literally metal things shop) Specially Selected.
SWMBO reckons that the two small characters on the right are Toku-Sen (specially selected) again but isn't 100% sure due to the small size in the photo.
Yamashita is a relatively common family name