The translation for GutterTrash into Japanese is still in progress, though hopefully it will be ready in the next month or two. The translation for the first game into Japanese is here, but keep in mind it was for an older version, so there may be some oddities (should mostly work fine though). Those are the only translations I'm aware of, though there may very well be other unofficial ones.
RPGMakerMVGame Hook patcher, Textractor. The first adds a plugin to RPGMaker MV games to spit text out to the clip board. The second can take this text, run it through translation, and display it to a window in realtime.
I'd recommend using the API access to Deepl available in Textractor; you'll need a key, but you can get that for free with signup, just need to give a cc to prevent abuse. That'll give you very good real-time machine translation. If you want to actually translate the game, I'd recommend Translator++. It's specifically designed to work with RPGMaker games (among others), and helps you keep track of where you are in the translation project, entry by entry. You COULD just end the files directly, they're all unencrypted text, but that could get messy quickly.
Read the info at the links given, most of what you need is there. I understand not everyone knows the layout of an RPGMaker game though: most of the text (dialog, item names and descriptions etc) is stored in various text files in the data folder. It can be a lot to dig through in raw text though, which again is why I recommend Translator++: you just point it at the directory and it should be able to figure everything out on its own and load things up. If you have specific questions, feel free to ask though.