Makita Hikari is a police officer. She has a pure personality and doesn't question people’s motives. Due to her personality, she is constantly deceived by suspects and finds herself relegated to a trivial job in the cold case resource room. One day, a mysterious man, Chajima Ryunosuke appears. Through Chajima, Hikari begins works in the newly formed Cold Case Anonymous Investigation Unit of the Tokyo Metropolitan Police Department. The department tackles unsolved
