The Crown will withdraw an additional charge of burglary during sentencing.
Mr Smith said Paku's relationship with Tamati Reihana ended towards the end of 2011 before Reihana moved in with someone else in Mill Rd, Whangarei.
The new relationship upset Paku to the extent that harsh texts and Facebook messages were exchanged, he said.
On the afternoon of November 8, 2011, Mr Smith said a confrontation between Paku and Mr Reihana triggered what had happened that evening.
About 8.30pm, he said, Paku and her siblings went to the Mill Rd address, entered a bedroom where Mr Reihana and his new partner were and set upon them. A machete, gas bottle and punches were used on the couple and items in the bedroom were damaged.
A 14-year-old boy who heard the commotion and tried to intervene was knocked unconscious, he told the jury.
Mr Smith said the new partner had run outside and tried to flag passing cars, with blood pouring down her body. He said police arrived fairly quickly but none of the siblings was located that night.
Judge John McDonald thanked the jurors for their patience before discharging them after the rest of the four defendants pleaded guilty.
All were released on bail to re-appear for sentencing on March 22.
