He finished the year second in the championship standings behind future Toyota Gazoo Racing WRT driver Takamoto Katsuta.

[9] After the Japanese F3 season concluded, Hirakawa made his debut in the Macau Grand Prix with RSS, qualifying 24th and retiring from the race due to a collision.

Hirakawa joined the Toyota Young Driver Program (TDP) and made his Super Formula Championship debut in 2013 with the Toyota-powered Team LeMans.

[14] After two seasons away from the series, Hirakawa rejoined the Super Formula grid in 2018, driving for Team Impul alongside Yuhi Sekiguchi.

He won his first pole position at the second round in Autopolis, but the race was cancelled due to heavy rain and fog.

The duo of Hirakawa and Cassidy won the opening round at Okayama, leading an all-Lexus sweep of the top six positions.

[23] They won again from pole position in the penultimate round at Chang International Circuit in Thailand, before clinching the GT500 championship with a second-place finish at the finale at Motegi.

[11] Hirakawa and Cassidy would seek to defend their championships in 2018, but faced strong competition from an improved Honda fleet led by Team Kunimitsu and their drivers, Naoki Yamamoto and newcomer Jenson Button.

[24] In 2019, Hirakawa and Cassidy once again finished second in the drivers' championship, just two points behind manufacturer stablemates Kazuya Oshima and Kenta Yamashita at Team LeMans.

Hirakawa and Cassidy won the opening round at Fuji Speedway from pole position, giving the new Toyota GR Supra GT500 a win in its debut race.

[28] After retiring from the sixth round at Suzuka due to a pit entry collision, Cassidy left the series in order to focus on his new role as a driver for Envision Virgin Racing in Formula E. Hirakawa and his new co-driver Kenta Yamashita won pole for the final round at Fuji Speedway.

[31] On 4 February 2016, Toyota Gazoo Racing announced that Hirakawa would be competing in the LMP2 class of the European Le Mans Series.

He also competed in the 24 Hours of Le Mans for the first time in 2016, and was in contention for an LMP2 class podium finish before Thiriet suffered an accident early in the morning on Sunday.

[33] For 2017, Hirakawa joined the number 22 G-Drive Racing entry operated by DragonSpeed, partnering Memo Rojas and Léo Roussel.

In his first time challenging for the overall victory, Hirakawa became only the sixth Japanese driver to win a leg of the Triple Crown of Motorsport, succeeding fellow Le Mans winners Masanori Sekiya, Seiji Ara, Kamui Kobayashi, and Nakajima, and Indianapolis 500 winner Takuma Sato.

He succeeded Nakajima, Kobayashi, and Toshihiro Arai as the fourth Japanese driver to win an FIA-sanctioned world championship.

[36][37] On 12 October 2023, Hirakawa tested Formula One machinery for the first time, driving the team's 2021-spec MCL35M at the Circuit de Barcelona-Catalunya alongside Pato O'Ward.

[38] Hirakawa made his debut in a Formula One race weekend at the 2024 Abu Dhabi Grand Prix, driving the McLaren MCL38 in the first practice session in place of Oscar Piastri.

Hirakawa will pair with Esteban Ocon in order to fulfill FIA requirements for Young Driver participation (those with two or fewer F1 starts) as Oliver Bearman is ineligible after competing in three Grand Prix events in 2024.