Convert text using a punctuation mark
From the Input menu in the menu bar, choose a Japanese input source, then choose Open Japanese Preferences. Then, make sure the following options are set:
Deselect the Live Conversion checkbox to turn off Live Conversion.
Select “Convert with punctuation.”
Click the Punctuation pop-up menu, then choose the pair of marks you want to use.
In your document, type a punctuation mark (such as 。or 、) to convert text, instead of pressing the Space bar.
If you type one of the marks in the pair, that mark is entered. To enter the other one, press and hold the Option key while typing the mark.