[2][3] At the start of the 2023 season, Hayakawa officially signed a first-team contract with the club;[4][5] on 5 April, at the age of 17 years and four months, he made his professional debut, coming on as a substitute for Kai Matsuzaki in the 76th minute of a goalless J.League Cup draw against Kawasaki Frontale.
[6][7] On 19 April, he started and scored his first professional goal in a 1–1 league cup draw against Shonan Bellmare:[8][9] at 17 years and 134 days, he became Urawa's youngest goalscorer in any J.League-hosted competition.
[9] Finally, on 23 April, he made his league debut as a substitute for Takahiro Sekine in the 80th minute of a 1–1 draw against Kawasaki Frontale.
[10][11] On 30 April 2023, Hayakawa made his AFC Champions League debut, coming on as a substitute for Tomoaki Okubo in the 81st minute of the first leg of the 2022 ACL final against Al Hilal, which ended in a 1–1 draw.
[26] In May 2023, he was included in the Japanese squad that took part in the Maurice Revello Tournament in France,[27][28] where the Samurai Blue finished tenth, after losing to the U-21 Mediterranean Team in the final play-off.