Nick Hewson's unblemished run as captain of Hong Kong is in danger of coming to an end on Sunday in Tokyo unless his side can "express themselves and not worry too much about what Japan will do" in the finale to the Asian Five Nations. Hewson has a 5-0 win-loss record as captain going into the high-stakes match, which will decide Asia's representative at the 2015 World Cup in England. The winners will book a berth in pool B alongside South Africa, Samoa, Scotland and the United States. The losers will face Uruguay in the first stage of the repêchage. The biggest worry for us is thinking about them too much rather than getting our process right. We have some quality players and we need them to be confident in expressing themselves Nick Hewson A bustling blindside flanker, Hewson hasn't tasted defeat since being given the captain's armband last December in the two-test home series against Belgium. with Hong Kong winning 28-17 and 18-15. Japan, who are 13th in the IRB world rankings, will be his biggest test yet but Hewson says his side are looking forward to the tough challenge against a side boosted by three Super Rugby players. "The biggest worry for us is thinking about them too much rather than getting our process right," Hewson said. "We have some quality players and we need them to be confident in expressing themselves." Hong Kong have made one change to the line-up that started in the 39-6 win over South Korea a fortnight ago, with hooker Alex Harris coming in to replace Tom Bolland, who is unavailable. There are also three new faces on the bench – hooker Lachlan Chubb, scrum-half Kenneth Hsieh and full-back Tom McColl. "We have to stick to our game plan and play rugby when we get the ball. We must make certain that when we get the opportunity to attack we take it with confidence, just like we did against South Korea," Hewson said. "But I'm not underestimating the massive challenge facing us, with Japan having called back all their Super Rugby players. This is exciting for us to measure up against this calibre of opposition." Japan are outright favourites to win the game – the Brave Blossoms have not lost a match in the ARFU Asian Five Nations since its inception in 2008 and have posted more than 50 points against Hong Kong on the three occassions they have played at home. However, head coach Eddie Jones is wary of the dangers Hong Kong will bring and has hammered into his side that a win is all that matters at the National Olympic Stadium in Tokyo. "All we have to do is to win. We don't have to play fantastic rugby, though it would be nice as there will be a big crowd. But if we have to grind out a 12-6 win then that's what we will do," Jones said. "This is the most important game of the year so far for us and we are expecting Hong Kong to be very physical. This being the last qualifying match [for the World Cup] we are very respectful of Hong Kong but also confident." Japan crushed the Philippines 99-10, Sri Lanka 132-10 and South Korea 62-5 to stand on the verge of representing Asia for the eighth successive time at the World Cup. Hong Kong's run has also been impressive – they have beaten the Philippines 108-0, Sri Lanka 41-10 and Korea 39-6, conceding only one try in 240 minutes. Jones is well aware of Hong Kong's tough defensive qualities, and this has probably been the reason behind him enticing Hong Kong head coach Leigh Jones to join the Brave Blossoms .