If you get injured in Japan, finding a hospital with English support can be challenging, even in Tokyo. While good hospitals are plentiful, only larger ones typically offer English assistance. However, you can easily navigate this with the help of the website linked at the end.
This site also provides some helpful answers to some questions you may have like “What happens at a clinic or hospital?”, “What if it’s outside normal hours?”, “Do I need travel insurance in Japan?”, etc. I highly recommend reading through this page ideally before you even arrive in Japan so you’re prepared well in advance.
English-speaking hospitals in Tokyo: https://tokyocheapo.com/lifestyle/english-speaking-hospitals-tokyo/