I always try to give a practical answer.
1. An actual katana is a war tool, not a chopping tool.
2. If you want a chopping tool, buy a machete and chop to your heart's content. They were used effectively in the Philippines against the US Army in 1900 and against the Japanese in WW2. I own some, and they work and are very practical.
3. Your friend should take an escrima course before deciding to buy a katana. The movements in knife fighting, escrima fighting and sword fighting are the same. Simply holding up a sword does NOT transfer skills to the holder. There are a limited number of movements and they can be mastered fairly quickly, followed by repetition.
4. I have a number of different swords, including a not cheap, not practical katana and two wakazashi swords. I would never use them to chop things.
5. Read this article:
https://en.wikipedia.org/wiki/Bokken Of course, I train with a Cold Steel boken. Much cheaper than a katana. Safer. And, in the hands of trained person, it will be a deadly weapon. Sometimes you can make items. In escrima, the practice is with bamboo that can break. I had a guy at a range ask me to show people an escrima stick. I brought out a practice stick and he deliberately broke it. I asked to wait a minute and I went to my car and brought a home-made escrima stick made of cast iron water pipe with end caps and asked to break it. He passed on that.
