How do you spell

[Kai Hyuga]

I am pretty sure that it can be spelled both ways as well, Hyuga or Hyuuga, whatever, and I am pretty sure it is Gai as well.  

[churrlo]

They write it Hyuuga because it's a long vowel blaugh  

[Mirrored Reflection]

Purple dragon lady

xxrokixx

i think its hyuga but in the un-translated version in the sub titles it says Hyuuga.....yeah i've always been confused about that to...(RANDOM: and do you spell his name Might Guy or Mite Gui i've seen it both ways)

I think its Gai.

Officially It's Might Guy. According to Japanese transliteration, it becomes Maito Gai. However, if you were also to transliterate Lee's name in the same way, you'd probably still call him Lee, however according to "the correct Japanization" you guys would be calling him "Rokku Rī". However, you're not, so his name is indefinitely Might Guy.
And while I'm here, you're both wrong. It's Hyūga, with the circumflex. However, according to the laws of transliteration, it's Hyuga. Although in fandom, to many people it's Hyuuga, because the circumflex is usually read as an extra vowel, as in Winrī (character in FMA) or Kōichi Tōchika (Neji's seiyuu). Just trying to clear things up.  

[The World Within]

i think hyuuga
but ive seen it both ways.
both are right? whee