The NZ Nationals are for ages 10 & up, competing in premeire divisions. The NZ Cup are for all divisions under 9, along with 10 & up intermediate and develop divisions.

NZ National Karate Championships - Saturday 27th August
NZ Cup - Sunday 28th August
Venue: Barfoot and Thompson Stadium, 203 Kohimarama Road, Kohimarama, Auckland 1071

Find more info on sportdata: 
https://www.sportdata.org/karate/set-online/veranstaltung_info_main.php?active_menu=calendar&vernr=6524#a_eventhead