South Africa's history-making rugby captain Siya Kolisi is looking forward to Saturday's Rugby World Cup final in Japan, but has acknowledged that the role initially "took its toll" on him.

The 28-year-old is the first black Springboks captain, a role he has held since June 2018, soon after Rassie Erasmus became coach.

"It was very tough at the beginning," Kolisi said.

"When it got announced, it was a big thing back at home and around the world. It took its toll on me at the beginning and my performance dipped quite a lot."

"We played England in that June series and I wasn't playing at my best. I think it was just a bit too much, so I had to work hard on myself.”

Back in top for now, the star has led his side to the final of the 2019 Rugby World Cup in Japan, which will see them play against an inspired England side. He said the Springboks will take inspiration from the huge support they have received from South Africans back home.

"We know how much rugby means to the country and what it has done in the past. We have the country behind us, which is something huge … I can't imagine what it would be like (in South Africa if) we win the trophy," he said.

The final will be played at the International Stadium Yokohama, a 72,000-seater facility in Yokohama city. Among the fans that will be in the venue watching is Fezakele Kolisi.

Saturday will be a momentous time for both Fezakele and his son. While the younger Kolisi will be battling for his country's third World Cup title, his father will be watching him live for just the second time.

Ahead of the game, President Cyril Ramaphosa, who is already in Japan for the game, has sent his best wishes to the Springboks and also rallied his country to support the team.

"I am quite excited. I am going to meet our rugby team and I'm looking forward to seeing them in their camp and giving them a lot of encouragement and vuma from 57 million South Africans who are standing behind them and wishing them the very best in their titanic battle with the English. I am hoping we will be able to defeat and annihilate the English and bring back the cup home. South Africa's moment has arrived," President Ramaphosa said before departing his country on Friday.