24 July 1979
|Revised Romanization||I Si-yeon|
|Revised Romanization||I Dae-hak|
Lee debuted as a male model under her birth name Dae-hak, becoming known for her feminine appearance and wearing women's clothing on the catwalk, but ultimately wished to pursue a career as an actor. She appeared in the films My Boss, My Hero (2001) and Sex Is Zero (2002), providing comic relief in effeminate male roles, but felt pressured into cutting her hair and building up muscle. Lee recalled that, "once I entered showbiz, I was forced to live a life I didn't like", and growing increasingly unhappy, made several attempts at suicide before deciding to become a woman.
Adopting the given name Si-yeon, Lee underwent sex reassignment surgery in 2007, and admitted to having doubts over her sexuality since being in secondary school. She returned to acting later that year in the sequel Sex Is Zero 2, with her character from the original film now also a transsexual. Lee publicly announced her sex change prior to the release of the film, but was apprehensive about the reaction from audiences. Co-star Shin-ee observed that surgery had not changed her image much, and stated that she had always regarded Lee as a "kid sister".
- Chang May Choon, "I have started my second life as a woman", Asiaone, 31 January 2008. Retrieved on 2 February 2008.
- Yang Sung-jin, "Sex is Zero 2 sticks to toilet and bawdy humor", The Korea Herald, 3 December 2007. A free copy of this article can be found at HanCinema. Retrieved on 16 January 2007.
- Park Si-soo, "Male-Turned-Female Actress Appears in Sex Is Zero Sequel", The Korea Times, 12 November 2007. Retrieved on 16 January 2008.