Bug Report (Suggestion for more characters support or any API to do that) :)

Type /ver NametagEdit and post the output.

• 4.0.2

What version of Bukkit/Spigot/PaperSpigot are you using? Type /ver

• Spigot 1.8.8

What plugins are you using? Type /plugins

• PermissionsEx, NameTagEdit, Essentials, PlaceholderAPI and ProtocolLib

Please explain your issue. How do you trigger it?
Just trying to use special characters like "ñ", it's a spanish server, just to write Owner, but in spanish (Dueño).

Are there any errors in the console? Please use: https://pastebin.com
No, it's just that thing (\u00F1 means "ñ" in unicode, some things support that unicode codes)

Are you using MySQL or FlatFile?