Yukari Seimiya

About

Yukari Seimiya is a Japanese trail runner and ultrarunner who has built a reputation as one of Japan's most versatile and competitive long-distance athletes, with a range that stretches from the marathon to hundred-mile mountain races. A GU Energy athlete, she won the Shin-Etsu Five Mountains Trail 110km in 21:35:55, won the Nobeyama Ultramarathon outright with a course record, and holds personal bests of 2:44:23 for the marathon and 8:32:20 for 100 kilometres — numbers that reflect the road-level speed underpinning her mountain endurance. Her most internationally visible result came at the 2024 Mt.FUJI 100 — the flagship Japanese ultra on the UTMB World Series and one of the sport's World Trail Majors — where she finished second in the women's race behind Courtney Dauwalter, establishing herself as Japan's top performer at that distance and generating wide attention in the Japanese running media. A consistent presence on the Japanese ultra circuit and increasingly visible on the international UTMB World Series stage, Seimiya is one of the faces of a growing generation of elite Japanese women who are taking on the world's biggest trail races.

Notable Wins

• — Shin-Etsu Five Mountains Trail 110km winner (21:35:55)
• — Nobeyama Ultramarathon winner (course record)
• — Mt.FUJI 100 2024 2nd (behind Courtney Dauwalter)

Race History