Han Yi-yeon
19 years old, 3rd year of high school
female students preparing for the college entrance exam
Han Seung-woo's younger sister
Han Seung-woo
27 years old
A third-year police officer who prepared for the police exam right after graduating from high school and became a police officer at the age of 24.
Han Yi-yeon's older brother
Kim Yohan
22 years old
A junior police officer who quickly graduated from the police academy and came under Han Seung-woo.
Lee Yeon's unrequited love(?)
