This is a rehost of @togenyan's former Yo-kai Watch 3 save editor, which was removed from his Github on December 20, 2018. This is the most stable version of the save editor, compatible with the EU/AU release of YKW3. A great place to find some info on adding Yo-kai is the Yo-kai Watch Wiki on Wikia, where I update info as it becomes available.
Well, there's a Wikia for knowing what to look for. If you're looking for the English translations, all are on the Wikia as well, as well as their Medallium number.
Yokai Watch 3 Editor is in english? I see translations but I don't know how to apply them. So I can see what the items and everything says...