What is the longest blade you carry in japan that is not double edged?

Question:

What is the longest blade you carry in japan that is not double edged? Like a pocket knife.

Answer:

Even a pocket knife can be too long, I wouldn't even carry one if I were there. I do carry a pocket knife with me, but rarely have a reason to use it. There, I wouldn't even bother. You can be arrested for carrying one,and they can hold you for two weeks without even charging you if they want.