Totally second that. I'm on OS X but I still have to use other editors when I have to edit Japanese texts (usually seeing them as comments in code and text parts in HTML).
Otherwise Sublime Text is awesome.
Same issue is reported in here too.
The most commonly used Japanese encodings are shift_jis, iso-2022-jp (jis) and euc (ujis). (And also UTF8 but that's supported already.)