In the link below I'm asking a question about language based subfolders and their affect on language in Google search results.
My question can be applied to all sites adding translations to their sites not just Japanese to English and vice versa which is what I'm using as an example.
Multilingual sites and Google search results, do subfolders really work?
Edit: I'm assuming the question was closed because I specifically referenced a domain of mine for context; although I feel the question itself is still generally relevant even with the domain, as I can find no specific information regarding subfolders affecting search results, I have removed it from the question.