Jones, the 6ft 10in line-out tower, could be the key figure in a match Wales simply have to win if they are to harbour genuine quarter-final hopes.
The Japanese coach, Osamu Koyabu, yesterday admitted: "We have never come up against a player as big as Jones, how to combat him has been giving us a headache. But we hope to surprise Wales with our sharpness and quickness and mixing things up at the line-out."
Jones, dropped by the old Wales management for the Five Nations wooden spoon decider against Ireland in March, is back in favour with the new team of the coach, the Australian Alex Evans, and the captain, Mike Hall, in a side showing eight changes from the side humbled by the Irish.
"It is superb to be back," Police constable Jones said. "We are all a bit nervous at the moment, there is an eager anticipation to get our tournament started, and we know we not only have to beat Japan, but we have to do it convincingly.
Japan defeated Romania 34-21 in Tokyo earlier this month, with five tries into the bargain, but Hall and Evans were both in bullish mood. "This side is as skilful as the Welsh sides of the Sixties and Seventies," Evans said. "But the recent teams have not had composure and that is something we have been working on."
Hall, winning his 40th cap but leading the side for the first time, added: "We want to prove the critics and sceptics, those who have written us off, wrong."
Wales, with the 20-year-old Bridgend wing, Gareth Thomas, and the Cardiff scrum-half, Andy Moore, making their Test debuts, should be able to control the match through their bigger pack.
Jones and Gareth Llewellyn will be banking on winning the crucial aerial battle against the Fijian-born Bruce Ferguson and Yoshihiko Sakuraba.
The South Sea Islands influence is enhanced by the Tongan back row men Sione Latu and Sinali Latu - no relation - and wing Lopeti Oto. But, even with the addition of their steel, the Welsh forwards should pack too much power.
The threat of record try scorer Ieuan Evans, who scored after just 56 seconds in the 55-5 Welsh win in October, 1993, adding to his 21-try collection has prompted the Japanese to opt for the strong defence of Oto.
And backing up the strike power of Evans and the new cap Thomas, a barnstorming 6ft 3in and 15st 11lb giant, is the boot of Neil Jenkins. The man who has amassed 358 points for his country in just 33 internationals has honed his skills at Springbok Park and with the benefit of the 4,664ft altitude has added another 15 yards to his kicking distance.
Wales, however, would prefer to win with the ball in hand. "If we reproduce the skills we have done in training the tries should come," Evans said.Reuse content