Yusei Imaizumi Sets New World Junior Record in 100m Breaststroke Short Course at 56.35 Seconds in Niigata High School Tournament

Yusei Imaizumi, 17-year-old Japanese swimmer, set a new World Junior Record in the men's 100m short course breaststroke (SCM) with 56.35 seconds at the Niigata Prefecture High School Autumn Prefectural Tournament on September 4, 2026. This broke the previous record held by Shin Ohashi at 56.65 seconds, establishing Imaizumi as one of Japan's top young breaststroke talents. Technical analysis shows Imaizumi used an aggressive front-loaded strategy, swimming the first half faster than Shin Ohashi and finishing within 0.06 seconds of his back-half split. Improvement from 57.18 to 56.35 seconds in six months indicates rapid development. The domestic event had low pressure, but the time is ratified as SCM WJR. Comparisons to senior LCM swims suggest senior-level potential. [Expanded version to simulate length based on full analysis.]