Yi (hiragana: , katakana: ) is a Japanese mora or a kana used to write it, though it has never been in standard use.Iannacone, Jake (2020). "Reply to The Origin of Hiragana /wu/ 平仮名のわ行うの字源に対する新たな発見"
History It is presumed that yi would have represented . Along with (ye) and (wu), the mora yi has no officially recognized kana, as these morae do not occur in native Japanese words; however, during the Meiji period, linguists almost unanimously agreed on the kana for yi, ye, and wu. (yi) and (wu) are thought to have never occurred as morae in Japanese, and (ye) was merged with and as a result of regular historical sound changes.
Characters In the Edo period and the Meiji period, some Japanese linguists tried to separate kana i and kana yi. The shapes of characters differed with each linguist. and were just two of many glyphs.
They were phonetic symbols to fill in the blanks of the gojūon table, but Japanese people did not separate them in normal writing.
i Traditional kana 綴字篇 (Hiragana) (Katakana)
yi Traditional kana (Hiragana) (A variant form of い. Hiragana.) (Katakana) Constructed kana 小学日本文典入門. 巻之1(い with dots. Hiragana.) 小学日本文典入門. 巻之1( with dots. Hiragana.) ( with dots. Katakana.) 新式漢文捷径初歩(A part of 以. Katakana.)
These suggestions were not accepted.
Unicode The hiragana form of this kana is encoded into Unicode as HENTAIGANA LETTER I-1, with the position of U+1B006, while the katakana is encoded as KATAKANA LETTER ARCHAIC YI, in the position U+1B120.
References
See also Ye (kana) Wu (kana)