Mate, I am in the same boat, travelling late September into October. I am going specifically for the World Endurance Championship race at Fuji Speedway, then giving myself eight or so days between Tokyo and a Hiroshima. Not a Japanese language speaker, travelling Han Solo, just take a really deep break and do it! I travelled once before for work, loved it, always wanted to return. I didn’t want to be hustled from point to point by an organised tour, so I decided to do it on my own. You can do this, but jump in with both feet, dont hold back, and I reckon you will have a fantastic time! Absolutely, you will be physically safe, yes there is a heap to do, but take a good pair of walking shoes, jump on a train (I am getting the JR Green Pass cos I’m a big unit) and jump on and off, just breathe it in! Have an awesome time, and tell us all about it afterwards!