In 2020, Tsuboi moved to the brand new TGR Team Wako's ROOKIE squad, driving the new Toyota GR Supra GT500. Alongside reigning GT500 champion Kazuya Oshima, Tsuboi scored back to back podium finishes to open the 2020 season. They finished the year seventh in the championship, recording a best finish of second at the fifth round at Fuji Speedway.