I'm interested in Japanese history and culture, so I thought I'd share this. There are a few small inaccuracies, but Petr (in the video) is clearly excited and respectful about participating, and works hard. So, I like it - and I hope you do too.
As I recall the Japanese technique of folding the metal back on itself repeatedly was the secret of the quality in a katana. As opposed to western Damascus steel which is a blending of different quality metals. I have watched too much Forged in Fire lately.