#but they COULD just have furigana. like haruno has since the beginning. hm

[cuchufletapl]

Is there a reason why some characters have kanji in their names and some don't?

I know that the kanji in Gaara's name have a narrative reason to be because they relate to his character ("one who loves himself", yeah, self-explanatory), and Haruno, Yamanaka, Nara, Akimichi, Aburame, Hyuuga, and Morino are all actual family names, but why are Naruto's and Sasuke's surnames always written in kana?

"Uzumaki" is an actual word, Naruto's surname in kanji could've easily been 「渦巻」. "Uchiha" is made-up, I think, but it's obviously based on "uchiwa" (which refers to the Japanese traditional fan that the clan uses as a symbol, and can also mean "family" or "inner circle"), so Kishimoto could've come up with something based on 「団扇」 or 「内輪」. I don't know.