So I have a few knives that were my dad's. He passed away last year and I've inherited them. The nakiri and the petty have the same Kanji. I am pretty sure he bought them in Japan while there on business at some point. The santoku I am not sure about. It looks cheaper, and says cosmic steel Kiya on it. Couldn't find much info on that. Any help would be appreciated. I'm not too concerned with how nice they are, more so for sentimental reasons (although I do plan on using them!). Thanks!