On 20 July 2021, Onaiwu moved abroad for the first time to join Ligue 2 side Toulouse.

[2] On 28 August 2023, he signed for Ligue 2 club Auxerre on a three-year contract.

[3] Onaiwu made his international debut for Japan on 11 June 2021 in a friendly match with Serbia.

Four days later, he scored a hat-trick against Kyrgyzstan at a FIFA World Cup qualifying match.

This biographical article related to a Japanese association football forward, born in the 1990s is a stub.