He experienced severe discrimination from Korean teammates referring to him as a ban-jjokbari (half-Jap) with strong racial undertones.

[8] He made his debut for Southampton on 28 January 2012, as a substitute in a fourth round FA Cup match against Millwall.

[9] Lee started and played the duration of the replay, failing to score as Millwall won 3–2 after a 92nd-minute winner from Liam Feeney.

[10] 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 scored by Rickie Lambert.

[citation needed] 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.

[19] After becoming a regular starter for Sanfrecce and finishing the 2010 season strongly, Lee was rewarded with a call-up to Japan's 2011 Asian Cup squad and made his full international debut on 9 January 2011 against Jordan.

[20] His first international goal was in the 109th minute of the final to secure a 1–0 win over Australia and Japan's fourth Asian Cup success.