What ￣ means
It is a standalone fullwidth overline, a bar rather than a sound.
Japan’s 1969 JIS X 0201 Roman set—a Japanese character-encoding standard—put an overline in the position used for ASCII’s tilde. The fullwidth form appeared in the 1978 JIS X 0208 punctuation table, so Japanese text could use that bar in a fullwidth character cell, about the width of a typical Japanese character. Japanese coding tables called the old slot “overline, logical negation sign,” while Unicode names this character FULLWIDTH MACRON. The changing labels reflect standards history; they do not make this a bar that attaches to a letter.
Why isn't ￣ the Japanese long-vowel mark?
No: ￣ does not lengthen a Japanese vowel. In Japanese katakana, ー—the long-vowel mark, called 長音符—extends the preceding vowel; JIS lists it separately from the overline slot. ￣ stays in its own cell and does not attach over following letters. Use a combining overline or text formatting when the bar must sit over a letter.
Why does ￣ sometimes turn into another bar?
Older Japanese conversion profiles can change which bar appears. The same legacy overline slot is documented as ￣ in one profile and ‾ in another; Windows-oriented mappings can resolve it to ￣. This is a data-conversion difference, not a new meaning in a message. When exact identity matters, preserve the source encoding and conversion profile.
Technical and legacy; it reads like a character-set or typesetting artifact, not a casual reaction.
Do not use it for Japanese vowel length; use ー instead.
Don't confuse it with
3Questions people ask
1Will ￣ sit over the next letter?
No. It occupies its own cell; use a combining overline or text formatting when the bar must attach.
How to type ￣
￣\FFE3Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.