She said they were using props to get across their theme, which included hiding behind masks and using a broken mirror in the set.
The Rotorua regional competition will be held across two nights at the Civic Theatre on Monday and Tuesday.
Harriet said the best way to describe the event was "a big dance party".
"It is very rowdy [back stage]. If there is any chant-off you battle against the other schools and you have no voice by the end of the night."
Lakes High producer and Year 13 student Fenella Richards, 17, designed the set for the performance and said the school had been preparing since the start of the year.
"We would like to get a placing this year, we haven't got a placing since 2009 but in the end it is about participating and having fun."
She said in all they had 90 students in the on-stage group, plus a lighting group and a hair and make-up group who worked backstage.
She said they also had parents, teachers and students working on the costumes.
The performing arts competition, which centres around dance, enters into its 21st year this year in New Zealand involving 16,000 participants from 200 schools.
Local high schools will compete in two competition categories including raw division, which means no sets, and open division.
The J Rock division is for primary and intermediate aged students.