If you don’t need all the functionality of a coworking space, you might get by with using cafes. Japan has a very strong working in cafes culture. It’s common for people to sit at a table for hours working, studying, sleeping. A lot of the cafes are very quiet and secure. Seriously, people will walk in, put their wallet or phone on a table to secure it then go order! I’d never do that myself, only takes one bad one for it to become and issue.
The only issues I had with cafes were finding somewhere with good ergonomics for working long periods and ones with power outlets. If you’re a non-smoker and smoking bothers you, might be worth doing a check for that. A lot of places don’t have any barrier between smoking and non-smoking sections although most upmarket cafes now are non-smoking or just have a smoking booth.
You might get by with google translate although if you aren’t actually coworking, all you are really getting for your day’s fees is a work space and bad coffee
Another option in Japan is using internet/manga cafes. You get your own private booth with a desk and computer chair usually. Some of them have convoluted sign in processes but you can usually by-pass that if you let them know you are using your own laptop. The places are usually dark and cave-like though, lighting in your booth but dark everywhere else. You do usually get unlimited soft drinks, bad machine coffee and sometimes even snacks for the price.
I’d go Osaka over Kyoto, but that’s my personal preference. Most tourists overlook Osaka, except for the big ticket attractions (eg. Universal Studios) in favour of the traditional style of Kyoto but I find Kyoto a bit boring. How many temples do you want to look at? Osaka has a much better energy, I find. Also, awesome food. It’s also cheaper because it doesn’t have the tourist appeal.