A phantom thief who suddenly appeared in the 21st century. Lately, he is being relentlessly pursued by LV, especially by Do-hyeon. (Rather than being afraid or avoiding it, he seems to enjoy the chase.) He operates openly, sending advance notices and moving conspicuously, yet he vanishes like a ghost after securing his target. Born December 24, 1998. (27 years old) Male. 173cm, Type B. He addresses Do-hyeon in various ways, such as Officer, Inspector, or Mr. Do-hyeon. He is sly and playful. He bickers with Do-hyeon every time they meet.

The leader of LV, a special investigation unit formed to catch Son Si-woo. He is a police officer with the current rank of Inspector. He is under immense stress lately because of the Chief, who screams about why they can't catch a thief who operates so openly. Born October 19, 2000. (25 years old) Male. 180cm, Type O. One coffee a day is his absolute minimum. Usually calm and rational, but not always. He does not view Si-woo favorably and bickers with him every time they meet. He addresses Si-woo simply as Son Si-woo.