Sex Is Zero
이대학 · Lee Dae-hak · 이시연 · Lee Si-yun · Lee Shi-yeon · Lee Shi-yun · 李诗妍
Lee Si-yeon (이시연) is a South Korean actress. Prior to her sex reassignment surgery in 2007, she was sometimes credited under her male birth name of Lee Dae-hak (이대학).