[5][6] In June 2022, he secured a gold medal in the men's 200m event at the 106th edition of the Japan Championships in Athletics.

[7] Koki Ueyama represented Japan at the 2023 Asian Athletics Championships and claimed a bronze medal in the men's 200m event.

He clinched a gold medal in the final of the men's 200m race, which turned out to be a close-fought contest as he edged past Saudi Arabia's Abdullah Abkar Mohammed by the barest of margins with only a difference of 0.03 seconds.

Initially, Qatari track and field athlete Femi Ogunode took the lead for the front half of the race, and Koki Ueyama then managed to claim the lead in the 200m final, and Koki eventually won the race with a timing of 20.60 seconds.

[13] He was also one of the members of the Japanese team which secured bronze in the men's 4 × 100 metres relay final during the 2022 Asian Games.