Jaesang is a sixth-dan black belt (the highest ranking in taekwondo being ninth-dan) and a senior instructor at Rotorua's Han Lee Taekwondo.
His father, grand master Han Lee, is one of only two eighth-dan black belts in the country and will also be involved.
Jaesang said he'd been looking at bringing this event to the city for a couple of years after putting a proposal forward to the Rotorua Lakes Council.
"I was thinking if we can host a tournament in Rotorua it would be really great. So I made a simple proposal and submitted it to the council and that was the beginning."
Alongside the 400 athletes taking part at the Energy Events Centre a total of 40 referees and plenty of supporters will also attend.
Jaesang said he would love to host a full taekwondo festival in the city in the future.
"There is a huge festival in South Korea called Hanmadang. It is the biggest taekwondo tournament in Korea and it attracts a lot of tourists from all around the world ... and it is not all about competition. It is a type of festival with fighting competitions, jump kicking competitions and plenty of other events.
"I want to organise that type of thing here in Rotorua."
Jaesang said 13 local athletes were taking part at the NZ Open from the Han Lee Taekwondo club. Taekwondo and judo are the only martial arts included at the Olympics.
- Tickets: $10 adults, under-10s $5 which covers entry for both days.