Background
Lee was born to third generation Zainichi Korean parents in Tanashi (present: Nishitokyo), Tokyo. His father was also a football player, who played for Yokohama Tristar Football Club in the Japan Soccer League.
李 忠成
Lee was born to third generation Zainichi Korean parents in Tanashi (present: Nishitokyo), Tokyo. His father was also a football player, who played for Yokohama Tristar Football Club in the Japan Soccer League.
He is sometimes known as "Chung". His Korean name is Lee Chung-Sung (Korean: 이충성, Hanja: 李 忠成) and also had used pass name Tadanari Ōyama (大山 忠成, Ōyama Tadanari). Japan
Lee started playing football at Komine Football Club and later moved to Yokogawa Musashino F.C.
In 2001 he joined Football Club Tokyo youth team and took second places at All Japan Club Youth Soccer tournament, Prince Takamado Cup and J. League Youth tournament.
He briefly joined training squads for the South of Korea U-19 and U-20 teams but not played at official games. He experienced severe discrimination from Korean teammates referring to him as a “half-Jap” with strong racial undertones.
He was promoted to Football Club Tokyo in 2004 and moved to Kashiwa Reysol in 2005 and later joined Sanfrecce Hiroshima in 2009. Lee competed for Japan at the 2008 Summer Olympics finals.
After becoming a regular starter for Sanfrecce and finishing the 2010 season strongly, Lee was rewarded with a call-up to Japan"s Asian Cup squad and made his full international debut on 9 January 2011 against Jordan.
Southampton
On 11 January 2012, Lee secured a work permit to allow him to play for Southampton, who confirmed the free transfer on 25 January 2012. He scored his first goal for Southampton in a 4–0 victory over Derby County on 18 February, with a "venomous strike into the far corner" of the goal. He made his first league start one week later, a 3–0 victory away at Watford, with Lee winning a penalty for the third goal from Rickie Lambert.
He has not played since 10 March 2012, after damaging ligaments and missing the rest of the season.
After 5 months out injured, he made his return to action with a goal in a 4–1 victory at Stevenage in the League Cup. He was handed the number 19 shirt for the 2013-2014 season after Southampton invited him back to the First Team.
He made his first return to the Southampton team after year when starting in the League Cup against Bristol City. On 14 January 2014 he was released from his contract at Southampton after a two-year spell.
Return to Japan
On 14 February 2013, Lee returned to his former club, Football Club Tokyo on loan until the end of June.
He made his debut on 2 March 2013, coming on as a 72nd-minute substitutee.