There is also an option for a third season, should the player fit in well.
Chemics coach Denis Betts admits that the Australian-Tongan is a player who has impressed him in recent years.
“We have been looking at him for a while now and I almost signed him a few years ago when the Bulls were in administration the first time around but he was pretty happy to stay where he was,” said Betts.
“We were after something different in a front-rower and he’s a big man, has good footwork, he can hit hard and he ticks all the boxes we were looking for on the playing side of things.
“But first and foremost we are getting a great character, a hard worker and he wants to improve and that is only going to enhance our playing staff and squad.
“There’s a good connection here and there’s some players already at our club that already know him.
“Their supporters have loved him and you can usually get a gauge from them on what they think of him. There’s always a buzz around the place when he gets the ball and we know that something will happen around him.
“We have some hard working and good forwards here at Widnes, but what we have been lacking is a player with a little bit more size and presence and hopefully Nas can bring that to us.”
Manuokafoa is looking forward to becoming part of the Vikings squad next season.
“I’m really happy to be joining the Widnes family. I know a lot of the boys there already. There are some great players at Widnes already and I just can’t wait to be a part of it.
“I met up with James [Rule, Widnes Vikings CEO] and Denis and we spoke about where the club is going and I’m pretty excited. I’m looking forward to coming to Widnes next season and ripping in.
“With the situation as it is at Bradford I needed to get my future sorted and I wanted security for my family. Denis has shown faith in me and I’m over the moon to be joining Widnes and enhancing the Club’s good name.
“The club is making so much progress, you can see that from where they were last year to where they are now and I want to help them get even better. I’m so happy I’ve got this opportunity and I can’t wait.
“For a front rower I’m heading into my peak and I want to better myself and improve. Widnes has some good young players coming through but I want to earn my spot in the team. I want to enjoy my game and improve week in week out.
“I’ll leave Bradford with some good memories and I’ve had a good three years there but you have to move on. I’ve made friends for life there, and the fans have been brilliant but this is a new chapter for me at Widnes.”