In Saga, at the Japanese national short-course championships, 21-year-old Tomoyuki Matsushita stopped the clock at 3:54,33. It is a new world record in the 400m individual medley — 0,48 seconds faster than Daiya Seto's mark from 2019.
Matsushita, a silver medalist at the 2024 Olympics and the 2025 World Championships, had long shown he was capable of more. In September he broke the Asian record in long course, and now he has carried that form into the 25-meter pool. The splits speak to a well-thought-out tactic: an aggressive butterfly 53,22, a confident backstroke through 1:53,61, a powerful breaststroke leg and a finishing freestyle 55,28.
The previous record had stood for nearly seven years. Seto set it in the International Swimming League, and since then no one had been able to dislodge it. Matsushita did not merely improve the time — he showed that the Japanese medley school remains at the summit, despite the emergence of young talents such as 17-year-old Yumeki Kojima and Shin Ohashi.
The rivalry within the Japanese national team plays a key role. Matsushita himself admitted that talk of world records with Ohashi had become commonplace. This is not merely competition for places on the team, but a constant incentive to raise the bar. His defeat by Kojima at the 2026 Asian Games only spurred him on.
Moving from long course to short course demands different tactics and technique. Matsushita approached the race like a 300-meter event, attacking from the first meters and saving strength for the finish. That approach allowed him not just to break the record, but to do so with a solid margin — the second-best result in the final belonged to 4:00.
Matsushita's record is part of a wave of achievements by Japanese swimmers in recent weeks. It confirms that in a country where the medley has deep traditions, a new generation is ready to scale the world's summits. For Matsushita himself, it is a step toward the status of a leader capable of competing with Léon Marchand not only in long course.
