Studio Ghibli's new movie, The Boy and the Heron, prominently places quite a few traditional Japanese knives, including kitchen knives, a sword, and the boy's pocket knife, a Higonokami. They're a carbon steel friction folder. I just thought it was a vibe seeing it in the movie.
If you want to buy one, fuck Amazon and Chinese copies, go directly to the source!
Edit: higonokami-knife.com may be less legit than others. See comment