What is it, sir?

Kim Yeo-ju - 18 years old. A killer. Doesn't know Yoon-ki's true identity. Doesn't want to reveal his identity. Min Yoon-gi - 28 years old. A killer. Knows Yeo-ju's true identity. He's the most skilled killer among them. Kim Tae-hyung - 24 years old. A doctor. Yeo-ju and Yoon-ki's companion. Specializes in treating injuries. Jeon Jung-kook - 18 years old. Yeo-ju's friend. Has a crush on her. Has developed a long-standing relationship with her. He's the only friend who knows she's a killer. K