Taieri College sees it as ''extreme'', and the 15-year-old has been told he will not be allowed to return to class until it has been rectified.
Kurtis' father Philip, of Dunedin, contacted the Otago Daily Times yesterday, angry his son had been given an ultimatum: cut your hair or you can't come back to class.
Kurtis' hair had been in a mohawk style - shaved short on the sides, but long on top - for the past four weeks, Philip Bain said.
''At first they wouldn't accept that. They said get rid of the back part. So, we did that.
''Then they said crop the top. So we did that, and they said that's not good enough, either.''
Now, the hair has been combed over, to look similar to American rapper Macklemore.
But the school still does not approve and has asked Kurtis to shave it all off.
''I said 'What's wrong with it?' and they said 'We just don't like it','' Mr Bain said.
''I'm refusing to do that. There is nothing wrong with the hairstyle.
''He will have to shave his head completely bald to go back to school, and I'm not going to go that far just so he can go back to school.''
Principal David Hunter said Taieri College had a very simple rule: hair had to be kept neat and tidy, and ''extreme versions'' of hairstyles were not allowed.
''It's our judgement that his hairstyle is heading towards the more extreme.
''We don't think it sits within our school guidelines.''
The college was in a ''damned if we do and damned if we don't'' situation, Mr Hunter said.
''If we don't put in a set of rules, we have anarchy.
''And if someone doesn't agree with a school rule, for whatever reason, and we don't enforce it, we have the same situation.
''We shouldn't apologise for sticking to school rules.''
Mr Hunter did not want the situation to escalate to the same level as that reached by St John's College (Hastings) pupil Lucan Battison (16), who successfully fought in court recently to keep his locks after he was suspended from school for refusing to cut his hair.
''We'll find some common ground and move forward. I don't want Kurtis' education to be compromised.''
Mr Hunter said he would like to see Kurtis' hair shortened on the top, so it was more in ''proportion'' with the lack of hair around the sides.
''I don't think that's a particularly untoward request, is it?
''We've got better battles that we would rather be having, than arguing with parents over haircuts. Goodness me.''
Mr Bain said he was angry it appeared his son was being singled out by Taieri College.
''I've seen other kids there with totally 'out of it' haircuts, and just because he trimmed it a bit more, they've turned around and said 'no, that's not acceptable'.''
''If you're going to single him out, why aren't you singling others out?''
Mr Bain said Kurtis was getting good grades at school, but conceded he had been in trouble in the past.
Mr Hunter disagreed with Mr Bain's claim there were other pupils at the school with extreme hairstyles.
''I can't name a pupil that has a haircut of similar style to what he has at this particular stage.''
Mr Bain said he would take his son to school again today in the hope an agreement could be reached.
