The former Fijian policeman spent two years in Belfast on his first foray into northern hemisphere rugby and played 26 games for the Irish province. He then moved to Montpellier in 2010 and helped them reach the French Championship final in 2011 and the quarter-finals of the Heineken Cup last season.
But while he will be looking to boost his side's chances of reach the last eight once again from Pool 5, he is also looking forward to meeting up with some old friends after the game. You can take the boy out of Belfast, but . . . .
"I still remember the cold of Belfast, but I loved that place. I'll always have a soft spot for Belfast because it is where I really started my professional rugby carer," sid the 26-year-old wing.
"Most of my friends are still playing for Ulster and it will be great to meet up with Darren Cave again. He is a very close friend and I named my son after him. Being so close to so many of the Ulster players will make this a very special game for me."
Nagusa won't be expecting any old pals acts on the day and will be hoping to add to the four Heineken Cup tries he scored last season as Fabien Galthie's side reached the quarter-finals for the first time. The two teams have never met before in Europe and their first clsh will be vital in one of the toughest Pools in the tournament.
While Ulster picked up four points from an opening night win over Leicester Tigers, Montpellier, minus their star wing, began with an impressive away victory at Benetton Treviso that included two vital second half tries.
"I haven't played the past couple of games because I was doing some fitness work. I had to lose weight," admitted a more streamlined Nagusa.
"I don't regret this, I needed to do it and gave it all I had, even though I feel like I've been tortured by the fitness coaches! I feel a lot fitter, better and I'm very happy. And if there's one team I want to play against, then it has to be Ulster.
"I'm happy to have people like Fabien Galthié and Stéphane Glas here to push me and bring out the best in me. I'm more confident now and I feel like I can do what I do best again - scoring tries.
"The game is obviously not about individuals, it's a team effort, but I think I can bring that extra edge again. This game will be a step up after Treviso and we know that if we want to qualify for the quarter-finals again we have to win our home games, if possible with a bonus point.
"It's the way it is. It will be a bigger game than the first one and I know Ulster will be coming here to win. No one trains to lose and they know if you lose a game in the Heineken Cup it's pretty much over."
Montpellier are unbeaten in five matches at home in the Top 14 and are currently vying with Heineken Cup champions Toulon and Toulouse for top spot with all three level on 27 points after nine rounds. They opened their season at Stade Yves du Manoir with a 2-22 draw with Toulon and have since put Toulouse (25-0) and ASM Clermont Auvergne (43-3) to the sword on their own patch.
So how does Naguca see this vital round two battle in Europe going? Will Montpellier's mighty pack, with the ferocious Georgian Manuka Gorgodze at its core, be the dominant force?
"Their pack and ours are pretty similar, a good balance between power and pace, and it should be an interesting battle in the scrum, in the lineout nd at the breakdown. Whoever wins that collision will win the game," said Naguca.
"Ulster have grown a lot as a team over the past three years. They've reached the final stages of the PRO12 and of the Heineken Cup - they've grown big!
"They have a quality squad, which is still pretty young. They like to play a fast flowing game, which suits their players. From hooker to the wings they're all very quick.
"We'll have to watch out for every single one of them - Paddy Jackson at 10, Luke Marshall at 12, Darren at 13, Andrew Trimble and Tommy Bowe on the wings. Then there is big Nick Williams at No 8.
"We'll also have to be disciplined on Saturday, because they have some amazing kickers in Ruan Pienaar and Paddy Jackson."