Furusato proved himself to be a remarkable young talent by winning his debut race at the 2021 Red Bull MotoGP Rookies Cup in Mugello and finishing the season 11th in the overall standings. Simultaneously, he competed in the Idemitsu Asia Talent Cup (IATC), where he achieved an overwhelming performance by winning all seven races of the season to clinch the championship title.

Subsequently, Furusato began his Moto3 career with Honda Team Asia in 2022, securing a season-best 14th place at the Japanese GP. The following year, 2023, he saw further success, earning 63 points, including a 2nd-place podium at the Thailand GP. In 2024, he started the season with a 3rd-place podium at the opening Qatar GP and consistently fought at the front, ultimately securing two 2nd-place finishes. In 2025, his fourth season in the class, he achieved his long-awaited maiden Moto3 victory at the Malaysian GP (Round 20).

In 2026, he will step up to the Moto2 class, competing for IDEMITSU Honda Team Asia.