Her momentum continued throughout 2011, winning the women's 48-kg category in the 47th Seoul Amateur Boxing Match in February, and by RSC (Referee Stopped Contest) in the 7th National Amateur Boxing Championships in March.
Lee Seung-bae, head coach of the Korean national boxing team, said Lee "has a very accurate left punch.
Five Senses of Eros was an omnibus film from five different directors, and in the segment "Believe in the Moment" three teenage couples decide to swap partners for 24 hours, played by Lee and her fellow up-and-coming actors Kim Dong-wook, Song Joong-ki, Shin Se-kyung, Jung Eui-chul and Lee Sung-min.
In the comedy Descendants of Hong Gil-dong (also known as The Righteous Thief), Lee played the love interest of Lee Beom-soo, whose character is the 18th descendant of Hong Gil-dong, a Joseon-era Robin Hood whose family for generations has passed down the tradition of stealing only from the rich and giving to the poor while keeping their actions secret.
But Lee rose to mainstream popularity when she joined the cast of We Got Married, a reality show about fake married couples, and was paired with Jun Jin of the boy band Shinhwa.
Called the "Gundam couple" Later that year, she starred in Playful Kiss, another series adapted from a manga (in Itazura na Kiss, her character is Sasuiko, a haughty paragon of perfection who becomes the heroine's rival in love).
A staffer said, "But no matter how hard we try to dissuade her, she doesn't want to quit." To the surprise of fans and experts alike, Lee entered and won the 7th Annual Women's Amateur Boxing Competition in 2010, and the women's 50-kg category in the 10th KBI National Lifestyle Athletics Boxing Championship in November of that same year.
But Lee was unable to participate in the Asian Games when she failed to enter the March 2014 final tryouts (as well as the two previous ones).
Kim Won-chan, manager of the Incheon City boxing team, said, "She didn't have enough time to build up her skills for the bout.
Lee returned to the romantic comedy genre in 2013 with How to Use Guys with Secret Tips, playing an overworked and undervalued assistant director who one day buys an inspirational video, "Instructions on How to Use Men," and reluctantly follows its guidelines.
She becomes drastically transformed into a woman much-sought after by all men, including a top actor (played by Oh Jung-se).
Lee made her acting debut in 2008 in a guest appearance on season 3 of the TV procedural Urban Legends Deja Vu, followed by the historical drama The Kingdom of The Winds.