ヺ

• IPA^(key): [vo̞]
• IPA^(key): [bo̞] (some speakers, especially older people)

ヺ • (vo) 

1. (rare, dated) The katakana syllable ヺ (vo). Its equivalent in hiragana is を゙ (vo).

• The katakana syllabary is used primarily for transcription of foreign language words into Japanese and the writing of gairaigo (loan words), as well as to represent onomatopoeias, technical and scientific terms, and the names of plants, animals, and minerals. It is also occasionally used in some words for emphasis, or to ease reading; katakana may be preferred for words becoming buried in the text if they are written under their canonical form in hiragana. Names of Japanese companies, as well as certain Japanese language words such as colloquial terms, are also sometimes written in katakana rather than the other systems. Formerly, female first names would often be written in katakana.
• This is a relatively recent addition to kana usage to represent the non-native sound vo. As such, this is only found in borrowed words. Many speakers, especially older people, may pronounce this more as bo, [bo̞].
• This kana is rarely used, with ヴォ seeing more use.

• ヴォ (vo)

• (Katakana) 片仮名; アァ, イィ, ウゥヴ, エェ(𛀀), オォ, カヵガ, キギ, クグ, ケヶゲ, コゴ, サザ, シジ, スズ, セゼ, ソゾ, タダ, チヂ, ツッヅ, テデ, トド, ナ, ニ, ヌ, ネ, ノ, ハバパ, ヒビピ, フブプ, ヘベペ, ホボポ, マ, ミ, ム, メ, モ, ヤャ, 𛄠 (𛄠), ユュ, エ/𛄡 (𛄡), ヨョ, ララ゚, リリ゚, ルル゚, レレ゚, ロロ゚, ワヮヷ, ヰヸ, 𛄢 (𛄢), ヱヹ, ヲヺ, ン, ー, ヽ, ヾ