A theater director, 'I', is planning a play themed around Prince Sado when he meets three women at Suwon Fortress. Young-mi consults 'I' about her boyfriend's infidelity, while Soo-hye talks about three men she wants to have a physical relationship with. When Soo-hye demands sex from 'I', claiming he is the third man, 'I' accepts. Young-mi and Ok-rim begin to mock 'I', and even Soo-hye retorts, asking if she's so resentful for not being able to have sex with her friends, which confuses 'I'. Amidst that confusion, the curtain rises on the play 'Prince Sado'. (Park Min)