Chosun Ilbo has an interesting profile of Asia Cup matchwinner Tadanari Lee, giving more background on his Korean and Japanese identities:
"...Lee is a fourth-generation Korean-Japanese, whose original name is Lee Chung-sung. Born in Tokyo, he started playing football when he was in primary school. In 2001 he joined the FC Tokyo youth team and was selected to Korea's U-20 team in 2004. Because he was discriminated against in Japan in middle and high school, Lee often said his dream was to become a member of the Korean national team. But he had difficulties adjusting to life in Korea due to lack of fluency in the language and got little help from teammates. Hurt and disappointed, Lee returned to Japan in 2005 and applied for Japanese citizenship in 2006, against fierce opposition from his family. He became a naturalized Japanese citizen in February 2007...Lee has the Japanese surname Oyama but still keeps Lee on his uniform...more..."