Some idiot in Japan doing art work used "Holo" instead of "Horo" (I dunno, failed romaji in school, didn't get the memo on modern romaji)? So there's been this little slap-fight over it ever since (like the wikipedia war over the spelling -- many good arguments on both sides but I tend to support "Horo" as
I haven't seen a published book using ー'lo' for ’ほろ’ （ホロ) in years (or any kana chart that translates the "r" row as "l"). Also, when the actors say "Chloe" (Kuroe) you can hear them shooting for an "L" sound.... whereas "Horo" dives directly for the "r". Obviously we could argue about that forever.
The best argument *for* "Holo" seems to be that it is written in katakana... but there really aren't any European names like that (as there is for Lawrence Kraft). The best argument *for* "Horo" seems to be the Ainu word-for-wolf connection (horokeu), but there's that katakana issue.
To me, the katakana issue is cleared up by looking at an Ainu dictionary --- Ainu words are written in katakana since they aren't "native Japanese" o.O -->
http://books.google.com/books?id=Cd0...=2_0#PPA138,M1 (scan down a bit for 'horokeu' and observe what japanese characters are used)
Heh, I do note the wikipedia war seems to have tilted to a solution but we have two major conflicting points as apparently Yen Press may be going with "Horo".
http://en.wikipedia.org/wiki/Spice_and_Wolf