I use this website https://app.immersivetranslate.com/ its very straightforward, there's free translations services available, but honestly the pay ones are much better OpenAI, Gemini, Claude; although OpenAI is the one I use, I haven't test the others, images are definitely tricky even more if its a scan from a physical book, there's a pdf pro option maybe it can get it done, look at the Kobo website https://www.kobo.com/jp/ja if you are lucky and find the book published there, with Calibre you can remove the DRM from your EPUB file and then with Immersive Translate you get your translation done within seconds.