Kojima Breaks 400m IM Asian Games Record with 4:07.02
Japan's Yumeki Kojima shattered the decade-old Asian Games record in Tokyo, finishing ahead of Olympic medalist Tomoyuki Matsushita.
Key points
- Yumeki Kojima won gold in the men's 400m IM with a time of 4:07.02 at the 2026 Asian Games.
- The result set a new World Junior Record and broke the Asian Games record held by Kosuke Hagino since 2014.
- Kojima outpaced Tomoyuki Matsushita, who finished second in 4:09.64 despite holding the Asian Record of 4:05.83.
The water at the Tokyo Aquatics Centre churned with white foam as Yumeki Kojima drove toward the wall. At seventeen, the Japanese teenager did not just win the men's 400m individual medley at the 2026 Asian Games; he demolished history. His final touch came in 4:07.02, a time that erased a standard set over a decade ago and secured gold with authority.
The victory was a statement of dominance in a race dominated by Japanese swimmers. Kojima outpaced Olympic silver medalist Tomoyuki Matsushita, who took silver in 4:09.64, and Wang Shun of China, who claimed bronze. According to SwimSwam, this performance marked Kojima's second World Junior Record at the event, following his earlier success in the 200m medley.
Overtaking the World Number One
Matsushita entered the pool as the reigning world number one, holding the Asian Record with a 4:05.83 set last month. He led Kojima through the butterfly and backstroke legs, establishing an early advantage. However, the dynamic shifted dramatically during the breaststroke. Kojima accelerated, closing the gap and matching his senior teammate's pace as they approached the final fifty meters of freestyle.
The final stretch was a blur of power and precision. Kojima posted a 26.85 split for the last 50m, a surge that left Matsushita behind. The veteran, who had anchored the men's 4x200m free relay the previous evening, seemed to lack the final explosive energy required to hold off the teenager. Kojima's relentless drive turned a competitive race into a personal best record.
Shattering Decades of Japanese Standards
The 4:07.02 mark was not just a win; it was an erasure of the past. Kojima broke his own World Junior Record of 4:08.69, which he had set at the Pan Pacific Championships earlier this year. More significantly, he surpassed the Asian Games record of 4:07.75 held by Kosuke Hagino. Hagino’s time had stood as the benchmark for the competition since 2014.
By shaving over a second and a half off his previous best, Kojima improved his standing in the all-time rankings. He is now the fourth-fastest men’s 400m IM performer in Japanese history in long course meters. This places him behind only Matsushita, Hagino, and Daiya Seto, a distinction achieved at the young age of seventeen.
Emerging as a Global Contender
The race highlights a generational shift in Japanese swimming. While Matsushita remains the current Asian and world leader on the board, Kojima’s trajectory suggests he is closing the gap rapidly. His performance in Tokyo signals a future where the two Japanese stars may continue to trade blows for the top spots in international competition.
Kojima’s consistency in the medley events has become a hallmark of his career. With two World Junior Records now to his name at the Asian Games, he has established himself as a formidable force. The swimming world will be watching closely to see if his ceiling matches the rapid pace of his recent improvements.
