Kosuke Mashiyama, a Japanese judoka, has decided to compete for the Mongolian national judo team.

The 27-year-old Japanese athlete competes in the men's 90 kg category. Under Japanese judo regulations, an athlete must abstain from competing for three years before representing another country. Due to this rule, Kosuke Mashiyama will be eligible to participate in international competitions for Mongolia starting in April 2027. Therefore, he will not be able to represent Mongolia at this year's World Judo Championships. Mashiyama is the first Japanese judoka to change his citizenship.

The social media page "Judo cam" reported on the transition: “Yes, Japanese judoka Kosuke Mashiyama will now compete for the Mongolian national team. He is an Asian and Japanese champion, as well as a gold medalist at the Baku and Tokyo Grand Slams. This is not the first instance. Before Mashiyama, Kaihan Takagi also left the Japanese national team. However, in the recent history of Japanese judo, such a transfer might lead other new athletes to join foreign national teams in the future. It is understandable that any national team would want to include a top Japanese athlete in their roster. From this, it appears that the mindset and principles established by the founders of judo are no longer as strict as before.”

Kosuke Mashiyama won gold at the 2019 Asian Championships, the 2021 Baku Grand Slam, and the 2022 Tokyo Grand Slam. Furthermore, he is a three-time champion of the All-Japan Judo Championships. Having not stepped on the tatami since competing at the Asian Championships in Hong Kong in 2024, he is currently training in Mongolia.

Published Date:2026-08-31