Junior career In 2015, Sasaki was the Asia Talent Cup champion and also competed in the
2015 Red Bull MotoGP Rookies Cup, winning a race in Silverstone, and finishing in second twice, and third twice, finishing the season third in the standings. In the
2016 Red Bull MotoGP Rookies Cup, Sasaki won four races, finished on the podium eleven times during the thirteen races, and never finished outside the top four, winning the title by 49 points.
Moto3 World Championship Gresini Racing Moto3 (2016) In the
2016 Moto3 World Championship, Sasaki made his Grand Prix debut with the
Gresini Racing team at the
Malaysian Grand Prix as the replacement rider for the injured
Enea Bastianini.
SIC Racing Team (2017) Sasaki was signed up to race in the
2017 Moto3 World Championship for
Sepang Racing Team, partnering
Adam Norrodin. Sasaki had an impressive rookie campaign, finishing in the points eight times, twice in the top-ten (eighth place in Mugello, and seventh at Phillip Island), and ended up winning rookie of the year, scoring 32 points, finishing 20th in the standings.
Petronas Sprinta Racing (2018–2019) Staying with Sepang SIC Racing Team for the
2018 Moto3 World Championship, Sasaki basically copied his 2017 campaign: he finished in the points eight times, his two best finishes were a seventh place in Austria, and an eighth place in Qatar, and finished the season 20th in the standings, with 50 points. For the
2019 Moto3 World Championship, Sasaki would stay with Petronas
Sepang Racing Team, but would be partnered by
John McPhee. Sasaki improved, with five top-ten finishes (fifth in Argentina, sixth in Britain, seventh in Australia, eighth in Barcelona, and ninth in Germany), 11-point scoring finishes, a pole position at the
Sachsenring, finishing the season with 62 points, and 20th in the standings.
Red Bull KTM Tech3 (2020–2021) Sasaki switched teams for the
2020 Moto3 World Championship, signing with Red Bull
KTM Tech3, to partner
Deniz Öncü. Sasaki and Öncü were very evenly matched during the year, Sasaki collecting 52 points, and Öncü 50. Sasaki finished in the points eight times, in the top-ten three times, and scored his first career Moto3 podium at
Aragón, seeing the checkered flag in second place, just 0.051 seconds behind
Jaume Masiá. Tech3 kept both Öncü and Sasaki for the
2021 season, and both riders improved. Sasaki especially started the season well, with a seventh place in Doha, a fourth place in Portimao, a fifth place in Jerez, a fifth place in Le Mans, and a fifth place in Mugello. On May 29, 2021, in the
2021 Italian motorcycle Grand Prix, Sasaki was involved in an accident with
Jason Dupasquier and
Jeremy Alcoba. Dupasquier succumbed to his injuries the following day. Following the accident, Sasaki did not participate in the following two races. He returned for Austria, finishing in fifth place, before scoring his only podium of the season in
Aragón, finishing third, with Öncü finishing second. He scored 120 points during the year, finishing ninth in the championship standings.
Sterilgarda Husqvarna Max (2022) For
2022, Sasaki was contracted to race for
Sterilgarda Husqvarna Max team, along with 2019 teammate
John McPhee.
Liqui Moly Husqvarna Intact GP (2023) In
2023 Moto3 World Championship, Sasaki was riding for Liqui Moly Husqvarna Intact GP.
Moto2 World Championship Yamaha VR46 Master Camp Team (2024) Sasaki joined the Yamaha VR46 Master Camp Team for the
2024 Moto2 Season, making his Moto2 debut partnering
Jeremy Alcoba.
RW-Idrofoglia Racing GP (2025-2026) After Yamaha VR46 Master Camp Team left the championship, Sasaki signed a two-year contract for
RW-Idrofoglia Racing GP. ==Career statistics==