South Africa are exasperated that, before their quarter-final on Sunday, the questions they are asked are invariably about their rivals and tournament hosts Japan, not the team rated New Zealand’s closest challengers for the trophy.

An article on their union’s website complained that “almost no questions” had been asked about the Springboks at their media conferences. “Japan, Japan, Japan has been the focus of attention. Expect more of the same tomorrow.”

Memories of the 2015 upset in Brighton linger on. The situation is partly South Africa’s fault for providing a Japanese interpreter for briefings where little or no English has been spoken. Only when there are players on parade such as the Tongan-born Uwe Helu, who does not speak Japanese, are translators provided for the English-speaking media.

“They are a tier one country and we are tier two,” said one official when asked why half the reporters in the room at Japan’s hotel were not provided with a translation. The implication was that it came down to money – New Zealand and Australia have also provided an interpreter here – but South Africa are not a team to arm with a grievance.

“If you have watched how we have played in the World Cup you can see how we will play on Sunday,” said Matt Proudfoot, South Africa’s forwards coach. “If you think it is going to be one-dimensional, then you have not noticed our evolution.”

Eben Etzebeth (in the green hat) takes part in a South Africa training session at the Fuchu Asahi Football Park. Photograph: Anne-Christine Poujoulat/AFP via Getty Images

When questioned about Brighton in 2015 – when Japan produced the greatest shock in a World Cup history by defeating South Africa – attention is deflected to last month in Kumagaya, where the Springboks won a warm-up game 41-7 against a team containing 11 of the starters who took the field last Sunday and beat Scotland last Sunday.

“We know that most people want Japan to win,” Proudfoot said. “This World Cup has been incredible and it is mind-blowing how efficient and well-presented this tournament has been. A passionate crowd will be against us, but it will be no different to playing in New Zealand or at Twickenham. I am already getting goose bumps thinking about it, not how the rest of the world wants us to get beaten.”

South Africa showed against Canada that they can play it fast and loose and will be able to call on their wing Cheslin Kolbe, a player who could easily fit into Japan’s side, after recovering from an ankle injury. “Dynamite comes in small packages,” said Kolbe when asked about his size.

The crackdown on high tackles will benefit Japan because as defenders go lower, there will be greater opportunity for offloads and width. “We know we will need to outwit South Africa,” said Helu. “They are a physical team and we have to be smarter in how we attack.

“We know where the space is, how to identify defenders and exploit them. They are different to other teams in that they work as a group when they attack, coming at you in twos and threes. We will keep tackling and come at them every time.”

Every Japan player at this tournament has said the same thing: we trust our leaders and the game plan. “We have been very strictly coached in training,” the hooker Atsushi Sakate said. Our reactions and decisions are very closely supervised.”

Which poses the question: can they think on their feet? South Africa intend to find out.