Troubleshoot Japanese on Mac when rectangles display
On your Mac, do any of the following:
If you see a rectangle instead of a symbol: The symbol you want may not be available in the font being used in the Candidate window. Click the Input menu in the menu bar, choose Open Japanese Preferences, click the Font pop-up menu, then choose a font.
If you’re using Live Conversion: Try turning it off. Converting every character may cause rectangles or wrong characters to display. Instead, use traditional conversion.