Fix Shift-JIS filenames on Mac

Question marks, empty boxes, or accented gibberish where Japanese filenames should be — the classic signature of Shift-JIS bytes decoded as UTF-8. Here is how to identify it and undo it.

How Shift-JIS damage looks

Shift-JIS-encoded Japanese decoded as UTF-8 produces dense runs of accented Latin letters and stray symbols (e.g. こんにちは), and characters that fall outside valid UTF-8 sequences render as question marks or boxes. If you received the file inside a ZIP made on Japanese Windows, Shift-JIS is almost certainly the culprit.

Restoring the original names

Mojifix reads the damaged bytes, recognizes the Shift-JIS pattern among other candidates (GBK, Big5, EUC-KR, NFD damage), and reconstructs the original Japanese names. Works on the ZIP itself or on already-extracted files, with a full preview before anything is renamed.

Characters that were truly destroyed in transit (bytes replaced by ? during a lossy copy) cannot be reinvented by any tool — Mojifix flags those explicitly instead of guessing, so you know exactly which names recovered cleanly.