Here is a photo of the knife I have had for 60 years.
If I can be brutally honest, this doesn't look authentic at all. My guess is that this is a fake Japanese marking done by a westerner. The first letter is "き" and that's a hiragana letter, but the font is so cheap, childish, and unprofessional. The next letter is a made-up kanji, and the last symbol in the box at the bottom is probably an imitation of a stamp.
For your reference, below is a real professional marking on a knife. You can clearly see the difference in quality and craftsmanship: