What ｡ means
It closes a sentence; 。 is the standard Japanese period.
Western influence, fiction and schooling spread Japanese punctuation in the nineteenth century. In 1969, the Japanese set JIS C 6220 encoded kana (Japanese syllabic signs) and punctuation one byte per character, including ｡. Unicode keeps it for older text mixing character widths.
Halfwidth Japanese punctuation has no fixed screen size; fonts and layout can change its spacing.
Neutral punctuation; its narrow form signals format, not tone.
Use 。 in standard Japanese prose; ｡ may look accidental.
Don't confuse it with
1Questions people ask
1Why does ｡ show as a box on some devices?
Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.
How to type ｡
｡\FF61Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.