Senseis Gcobani Maxama and Lwazi Finca, as well as Yongama Booi, have been included in the South African squad for the tournament, which will be held in Tokyo from November 22 to 24.
Both Maxama and Finca have represented the national team before, while Booi will be making her first appearance for her country.
Madibaz Sport karate manager Bernard Petersen said the style of karate they would be doing was kyokushin (ultimate truth).
"It is a full contact style of fighting, where the aim is to knock the opponent out or down," he said.
"This is a milestone for the university because karate has so many styles which are catered for in various world championship events.
"Kyokushin is different to other styles as it is full contact and there have hardly been any opportunities for these karatekas to compete internationally because of the nature of the style.
"We at the university are very proud of their achievements. They have proved to be successful despite facing many challenges, not least of which are the costs associated with competing at a high level."
Petersen added that the trio had been involved in a number of tournaments since last year to stand a chance of gaining national recognition.
"They had to participate in four different tournaments and they made their mark at each one," he said.
"The first was the All-Africa Continental tournament, held last year in July in Cape Town.
"This was followed by the Oyama Cup [African Karate Association champion of champions] in October and a round-robin tournament in Durban in April.
"Lastly, they competed in the South African Championships in July in Port Elizabeth.
"Sensei Maxama won two of the four tournaments and came third in another one, while sensei Finca participated in all the tournaments, finishing in the top eight.
"Senpai Booi was second in the SA championships."
Preparing to compete in the open weight champs against formidable opposition from countries such as Japan, Russia and Brazil, Petersen said the trio were working a lot on body conditioning, strength and stamina training.
"Also they are aiming to put on a few more kilograms because the tournament is an open weight, which means weight doesn't count.
"There is only one division, so a person might fight with someone who is much heavier than them.
"This is obviously a disadvantage and hence they are trying to bulk up for the world champs."
Caption: Madibaz karatekas (from left) Lwazi Finca, Yongama Booi and Gcobani Maxama have been selected for the South African squad to compete in the World Open Championships in Japan from November 22 to 24. Photo: Brittany Blaauw