You don’t need to know any Japanese to pretty easily navigate metro Japan. Basically everything in Tokyo that you need to read is in Japanese first and English second. The same is mostly true in Kyoto but to a lesser extent. If you have an internet connection the trains are so accurate that you don’t even need to know the name of the stop you’re getting off at. Google maps says “get on the 3:12 train and exit at 3:38” and it’s accurate enough that you hit your stops

If you want to leave metro Japan then it gets a lot harder with less English around and the people are less accommodating but it’s still pretty manageable. This was in 2018 so I would imagine there’s more English around but people are probably less sympathetic to tourists