Boo! I should really check here more often.
I like the idea of Hunter's name being in Kanji instead of Katakana because it reflects how people traditionally got their names. For instance, Nakagawa means central river so people with the surname of Nakagawa most likely had family near a major river. Also, the names can indicate jobs like how in English names Hatter and Miller reflected the persons specialty.
Hunter in Kanji I think plays on his line between Mira that goes something like this
Mira: "Why do they call you that?"
Hunter: "I...hunt."
(Paraphrasing, I don't have the book close right now so I can't look it up.)
FYI Masami's last name (Hidamura) means Secret Field Village, I don't remember if I've said that.