2026 JAPANESE SHORT COURSE CHAMPIONSHIPS
21-year-old Olympic silver medalist Tomoyuki Matsushita crushed a new World Record in the men’s short course 400 IM while racing on day two of the 2026 Japanese Short Course Championships in Saga Prefecture.
Matsushita blasted a new lifetime best of 3:54.33 to overtake the longstanding former World Record of 3:54.81 fellow Japanese Olympic medalist Daiya Seto established during the 2019 International Swimming League (ISL).
Tonight on his home soil, Matsushita led wire-to-wire, getting to the wall over five seconds ahead of the competition.
Asaki Nishikawa represented the only other swimmer to clear the 4:00 barrier, registering 3:59.94 for silver, while Raito Numata, just 17 years of age, rounded out the podium in 4:00.07.
Entering this competition, Matsushita’s lifetime best in the SCM 400 IM rested at the 4:00.44 he posted at the 2024 edition of this competition. That means the ace hacked over six seconds off that prior PB to become the fastest man in history.
Comparing Matsushita’s swim to Seto’s, it’s apparent the former was more patient on the front half, conserving enough energy to attack the breaststroke and freestyle legs.
| Matsushita’s New World Record – 3:54.33 | Daiya Seto‘s Old World Record – 3:54.81 |
| 53.22 | 52.35 |
| 1:00.39 | 59.05 |
| 1:05.44 | 1:06.50 |
| 55.28 | 56.91 |
Matsushita is the 4th-fastest man in history in the LCM 400 IM, courtesy of the 4:05.83 lifetime best he put on the books just last month, a time which destroyed the 4:08.62 he logged for silver behind French champion and World Record holder Leon Marchand.
Matsushita settled for Asian Games silver, with his time of 4:09.64 situated behind teammate Yumeki Kojima‘s new World Junior Record of 4:07.02. Matsushita’s time of 1:55.30 did garner him 200m IM gold there in Tokyo.
