Lealiifano deal includes Japan clause
The flexible contract will see the 16-Test utility remain with the Brumbies until at least the end of 2018, while enabling him to take up an option to play in Japan for the 2016/17 and 17/18 seasons.
"I'm really happy that they've allowed the flexibility for me to go to Japan," Lealiifano said.
"I think it was super important, I needed some financial stability as well as the ability to keep my dreams of representing the country alive.
"I felt like I needed a little bit of a change-up without leaving the Brumbies full-time. I'm glad all the stars have aligned and that I get the opportunity to go over there and experience a new culture."
Lealiifano said he has already spoken to a number of people about Rugby in Japan and was confident with his decision.
"Obviously I had a taste of Japan with the World XV game when I was there," Lealiifano said.
"I spoke to guys like Berrick Barnes and Robbie Deans about the Rugby over there, and of course Bernie [Stephen Larkham] has played and coached over there, so I was quite lucky to have their knowledge on what to expect in Japan."
The 28-year-old is currently the second-highest point scorer in Brumbies history with 635 points and is the eighth most-capped player in the team's history with 101 Super Rugby caps.
The gifted and versatile inside back made his debut for the Wallabies in 2013 against the British and Irish Lions in Brisbane, before going on to feature in the he Rugby Championship and year-end tour that same year where he notched a career-high 20 points in a clash with Wales at Millennium Stadium.
Lealiifano says his desire to continue representing his country played a key role in his decision to turn his back on lucrative offers to move to Europe.
"That was the deciding thing for me, I still think I've got more to give to Australian Rugby," he told reporters today.
"Definitely a lot of offers from Europe, the UK and stuff, but ideally I want to stay here as long as I can."
Lealiifano added that he was pleased to have his future sorted ahead of the 2016 Super Rugby season.
"The Brumbies have shown a lot of faith in me over the last nine years and I'm pleased we have been able to sort everything out so I can stay," he said.
"By 2018 I will have been in Canberra for 12 years, so this is very much home for me.
"Obviously re-signing is always good to get out of the way before the season," Lealiifano added.
"All the concentration is now on footy and I'm really excited about the future and where we [The Brumbies] can go.
"Working with Stephen Larkham I feel like my game has improved, so to have two more years to work with this coaching staff and the rest of the playing group is very exciting."
Of Lealiifano's 16 Test appearances, 14 have come in the starting line-up at inside centre.
His last outing in the gold jersey came in Paris in a 26-29 defeat to France on the 2014 year-end tour.
Lealiifano first arrived in Canberra from his home in Melbourne in 2007 where he linked up with the Brumbies Academy and the Canberra Vikings in the Australian Rugby Championship.
He debuted for the Brumbies in 2008 and has since racked up 101 caps for the side, taking him to eighth spot on the Brumbies most-capped list.
Lealiifano said the culture of the Brumbies was a big reason for him staying.
"The Rugby program here is a big reason why I'm staying," Lealiifano said.
"The culture that's set up here is fantastic and makes it very hard to leave. That's the biggest thing, you're trying to keep players here as long as you can and if your program is good you've got the best chance of doing that."
Lealiifano said he was pleased to be staying in Canberra.
"I'm definitely stoked," Lealiifano said.
"This place has played a big part in my life and in my journey growing up as well. I'm excited about what's ahead and I'm definitely happy being a part of such an amazing organisation."