That sounds like a bit of an odd way to name a monarch.
In Japan, it seems rare for an emperor to take the same name twice, if they ever did. I think this is also true in Korea, it´s predecessor states, and in China. But in any language influenced by Greek or Latin, or by a church that used either language, and their descendant cultures, it is common to take the name of a previous king (or possibly a Christian saint), or more specifically, to be given that name upon their christening shortly after birth or converting as adults, and upon the death of the previous king to choose one of their Christian names, and if this isn´t a new name like Stephen in England, to take a Roman (or Greek) numeral following it. Sometimes epithets are used like the Great, as in Alexander, who was technically Alexandros the III of Macedon, or the Confessor, as in Edward, King of the English, which is why there are in fact nine English kings with that name not eight.
Serenity is obviously a Greco-Latin name, and Princess Serenity had the same name, so it seems to be one given upon her birth. To be called Neo isn´t technically wrong but does seem like a very atypical way to refer to them. I don´t imagine that Japanese people spend a lot of time studying regnal naming habits from Europe, but they do hear about some of their own emperors in school and I can´t think of a reason why Japanese or East Asian habits would explain why this kind of name would be used for Neo Queen Serenity, not even as an overly literal translation.
It seems like if a person knows enough about English and Latin to generate the name Neo Queen Serenity, they would also know enough about these languages to know that is a very atypical way to refer to them.
In Japan, it seems rare for an emperor to take the same name twice, if they ever did. I think this is also true in Korea, it´s predecessor states, and in China. But in any language influenced by Greek or Latin, or by a church that used either language, and their descendant cultures, it is common to take the name of a previous king (or possibly a Christian saint), or more specifically, to be given that name upon their christening shortly after birth or converting as adults, and upon the death of the previous king to choose one of their Christian names, and if this isn´t a new name like Stephen in England, to take a Roman (or Greek) numeral following it. Sometimes epithets are used like the Great, as in Alexander, who was technically Alexandros the III of Macedon, or the Confessor, as in Edward, King of the English, which is why there are in fact nine English kings with that name not eight.
Serenity is obviously a Greco-Latin name, and Princess Serenity had the same name, so it seems to be one given upon her birth. To be called Neo isn´t technically wrong but does seem like a very atypical way to refer to them. I don´t imagine that Japanese people spend a lot of time studying regnal naming habits from Europe, but they do hear about some of their own emperors in school and I can´t think of a reason why Japanese or East Asian habits would explain why this kind of name would be used for Neo Queen Serenity, not even as an overly literal translation.
It seems like if a person knows enough about English and Latin to generate the name Neo Queen Serenity, they would also know enough about these languages to know that is a very atypical way to refer to them.