Onishi began his professional career with Ehime FC in 2013.
[2] On 30 December 2016, Onishi signed with the J3 promoted club, Azul Claro Numazu, from Ehime FC.
[3] On 26 December 2018, Onishi joined Kagoshima United FC, who had been promoted from the J2 league.
On 26 December 2022, Onishi officially transferred to the J3 club Vanraure Hachinohe for the upcoming 2023 season.
This biographical article related to a Japanese association football goalkeeper is a stub.