Debutants Matt McCullough and Wilson step up to the senior plate having made their first Ireland 'A' appearances together last March. Showing a good deal of eagerness in training, 2004 Ulster Player of the Year Wilson is ready for the step-up.
"I'm looking forward to playing in front of a big crowd - there's 30,000-35,000 expected at the stadium so it should be a great atmosphere," said the 23-year-old number 8, who has become a fixture in the Ulster side for the past two seasons.
"Personally, I want to play to the best of my ability, get the ball in hand and help out in attack.
"I want to hold onto my position for the next match so I'll be trying to make a good impression, but the most important thing is that we win and win well."
For Duffy, who captained the Ireland Schools side on their nine-match unbeaten tour of Australia in 1999, the Japanese Test offers him a deserved first senior start.
Duffy, a noted full-back, who recently re-signed on a two-year deal with recently relegated club NEC Harlequins, is mindful of Japan's pace out wide.
"We've watched a couple of videos of Japan's recent games and they move the ball very quickly. Their back three are quite quick and we'll have to play close attention to them when they're on the ball," said Duffy, a try-scorer against Scotland on his second senior appearance last February.
"(Daisuke) Ohata, who plays in the centre or on the wing, is one of their best players and works some very good combinations with the full-back."
Munster wing Horgan, without an international cap since February 2004, also feels the Japan rearguard will command most of Ireland's attentions.
"We've looked at their back three for a few days on video. We'll be out to target them on the attack, but will also have to be careful of turnovers and potential breakaways, especially with the speed they have across the backline," said the Corkman.