Seventeen-year-old Yumeki Kojima won the men’s 400-meter individual medley at the Asian Games on September 22 in 4:07.02, leading a Japanese one-two ahead of Tomoyuki Matsushita’s 4:09.64. The final took place at Tokyo Aquatics Centre, the swimming venue for the Aichi-Nagoya Games.[1][2][3]
His winning time broke the Games record. Japan Aquatics also reported it as a world junior record and a Japanese high school record, giving the performance significance beyond the gold medal.[2][5]
Two finals, two Japanese one-two finishes
Kojima turned the tables on Matsushita after their close contest over 200 meters two days earlier. In that race, Matsushita won in 1:55.30; Kojima took silver in 1:55.36, just six hundredths behind. The federation reported Kojima’s shorter-distance swim as another world junior and Japanese high school record.[4]
In the 400-meter final, the federation’s account describes Kojima closing on Matsushita during breaststroke before moving ahead in the final freestyle leg. His eventual winning margin was 2.62 seconds.[1][2]
| Swimmer / medal | Time |
|---|---|
| Yumeki Kojima / gold | 4:07.02 |
| Tomoyuki Matsushita / silver | 4:09.64 |
Source: Japanese Olympic Committee, September 22 results.[1]
What the records mean
Reuters reported that Kojima lowered the Games mark set by Kosuke Hagino in 2014. The previous time, 4:07.75, had stood for 12 years; Kojima improved it by 0.73 seconds. A Games record covers performances at this competition. It is distinct from an unrestricted world record or an Asian record.[5]
The world junior designation concerns an age category. The gold medal, meanwhile, came in the Games’ senior competition: an important distinction when assessing a teenage swimmer’s emergence.
A contender still in high school
The JOC lists Kojima’s birth date as December 20, 2008, and his affiliations as Toyokawa High School and Copin Sports Club Toyokawa. He was 17 at the Games.[3]
Japan’s sweep of the top two positions in both medley distances shows competitive depth, with neither swimmer dominating both finals. For Kojima, the immediate achievement is concrete: silver over 200 meters followed by gold over 400. The next measure of his progress will be how consistently he can reproduce this level against international opposition.
