First of all, domesticational translation is not localization. In English--
This is a Japanese work set in Japan, with Japanese people.
The provided furigana for a kanji compound that would normally be pronounced "sei-bo" instead spells out, 1:1, "Maria".
That same "Maria" is the epithet given to her at the end of the chapter. The word is deliberately used in a
Japanese context.
We're talking about a proper noun-- a name. You wouldn't do what you're suggesting in real life to someone with the name "Maria"-- "Mary" and "Maria" are only equivalent in the sense that they're cognates, not in the sense that you can arbitrarily substitute one for the other.
Your assertion hinges on what you cannot prove, and those assumptions aren't good enough to support the action of anglicizing a name that the author goes out of their way to spell out the way they do.
Your suggestion risks being incongruous with future writing in ways you're not even interested in considering. It is an outright alteration of content without consideration for authorial intent--
and that's despite you understanding some of that intent as it stands in this chapter.
Even if one were to do it, they'd have to explain the change, and at that point, it'd be better that it be clarified that "Maria" is cognate with "Mary"
in a translation note.
As I said in my original post, there's certainly a foreignizational case for “Maria”, but it's just not compelling to me in this case because most people are not going to make the connection. And your point about search engines is just… childish and nonserious.
You seriously do not understand literate adults in the Anglosphere if you think they're going to be flummoxed by reading "Maria" instead of "Mary". Numerous Americans and British people are named "Maria". Disney's
Hunchback of Notre Dame exists, and is well known.
You're being unnecessarily patronizing, if not sorely out of touch. Me trusting a reader to look up things they're unclear about-- much less a well known cognate pair-- isn't "childish" in the slightest.
Secondly, there is (as of yet) not a meaningful distinction between Mari–Mary and Mari–Maria.
I don't know what you're answering to, and I can't tell what point you're trying to make.