Thiim, one of Aston's regular FIA World Endurance Championship drivers, was selected to represent customer outfit D'station in Japan's premier sportscar series this season, replacing championship veteran Joao Paulo de Oliveira alongside Tomonobu Fujii for 2020.
D'station is also switching from Yokohama to Michelin tyres as Aston bids for a stronger showing in its second season of GT300 competition with the Vantage GT3.
Having never raced in Japan outside of the Fuji WEC round, Thiim says he is looking forward to racing in a new series and vying for honours as part of a bumper 30-car class field.
"Japan has a lot of history in racing, Tom Kristensen and a lot of other Danish drivers have been over there, so it’s an awesome championship and lets you tick the box of driving in Japan," Thiim told Motorsport.com. "Really looking forward to it.
"It will be a new challenge with a new team that is really competitive. It’s really hard to say what to expect. But I know from Aston’s side, it’s a big push to go out there and deliver, to put on a good show, because Japan is a big market for us.
"We know from the WEC that Michelin is the tyre that is developed for the car. So it shows that Aston is putting a lot of effort into it and sending a lot of people to support the team.
"As a driver, it sounds good. But let’s get out there and see. There are so many impressive-looking cars and competitive drivers. They have cars that you don’t see in Europe at all, like the new Supra. It’s a big championship."
Asked if he felt wins and a championship challenge could be possible from the off, Thiim replied: "I have zero feel for where we’re gonna be pace-wise.
"I know Aston and the team are trying to put together the best solution. But I can only say on paper it looks really good. It’s gonna be super-interesting. I’m excited for it.
"It’s gonna be a cool experience. It’s like British GT, it looks like, a lot of old-school racetracks that I’m used to and I really enjoy."
Thiim will be one of three European factory drivers in action in the GT300 class this season, joined by Christopher Mies, driving an Audi R8 LMS for the Hitotsuyama squad, and Lamborghini's Dennis Lind at the wheel of a Huracan GT3 for the JLOC outfit.