Small combining form of hiragana い(i) used to explicitly specify the vowel part of the previous hiragana character, or to show a speaker's pronunciation or extension of that vowel.
ふぃ - the sound [ɸi] rather than [ɸu] (ふ) or [çi] (ひ)
ふぃぎゅあ - transliteration of Script error: The function "cognate" does not exist.