Principal Geraldine Travers remembered the decade-old incident that inspired the girls: "It was the longest string of bras up the flagpole, with a sign saying 'thanks for the support'."
She said young people received a bad press but when it was innocent fun the prank-day tradition was "just lovely".
"It's what they do every year - the junior girls' eyes light up when they see what the seniors have done and they start thinking of what they can do."
Ms Travers did not escape the pranks, with her office plastered in pictures of a well-known politician: "I thought I'd taken them all down, but there was another on my desk in a silver frame - it looks like he's a revered member of my family."
Other pranks included "spookifying the staff room", filling the administration office with balloons, and glad-wrapping every item in the English department.
The senior girls also dressed in costume and scared teachers and students, with deputy head girl Rebecca Frankum saying the best costume was worn by head girl Katherine Winitana.
Zoe said some staff told her it was the most creative prank day the school had seen.
Most seniors' extravagant costumes meant they had to leave early to get cleaned up and did not witness the dismantling of the bra fence, which was gone by 3pm.
