Takumi Ominami was born on 13 December 1997 in Aichi. He came through Júbilo Iwata before joining Kawasaki Frontale, where he was part of one of the most-decorated periods in J1 history. With Frontale he won the Super Cup in 2024, the Emperor's Cup in 2023, and the EAFF E-1 Football Championship with Japan in 2022.
His Frontale career produced consistent J1 output. The 2023 season produced 29 J1 matches with an assist; 2024 brought 24 J1 matches plus 4 J.League Cup appearances. In summer 2024 he moved to Belgium with OH Leuven on loan, with a permanent move that proved complicated by multiple short-term moves between Frontale and Leuven across 2025. By the second half of 2025 he settled at OH Leuven full time.
The 2024 OH Leuven season produced 24 Belgian Pro League matches; 2025 produced 19 Pro League matches with an assist as Leuven's senior centre-back.
A 184cm two-footed centre-back with aerial presence, ball-playing security and the senior leadership of a Frontale-decorated defender, Ominami is one of Japan's most experienced multi-league centre-backs. He is a candidate for the wider 2026 FIFA World Cup squad as a senior CB option.