Song-jun Yoon

Yoon Sung-jun was born a second-generation Zainichi Korean in Osaka, and it is a Japanese club, not a Korean one, that raised him. He came through Kyoto Sanga's academy, moving up through the U-15 and U-18 sides before signing his first professional contract with the club in August 2024, at 17. His debut season made the wait worthwhile: given a start in Round 3 of the 2025 J1 League campaign against Avispa Fukuoka, he was named man of the match by the club's fans. He went on to make 18 league appearances that season, adding one assist, and was named J1 League Player of the Month for February 2025. Kyoto Sanga rewarded him with a renewed contract in July 2026.

His international situation is the more unusual part of the story. Yoon represented South Korea at U-18 level in 2025, the country of his family's heritage. Since then, he has begun the process of naturalising as a Japanese citizen, with a view to becoming eligible for Japan's youth national teams and, specifically, the squad being built for the 2028 Los Angeles Olympics. He has already been in contact with the Japan Football Association over the switch.

As a homegrown player who has never left Kyoto Sanga, he has progressed through the club's own academy, its partner side YF Nara Teshoro, and now its first team.