Gouriki plays the role of a newbie police officer Makita Hikari who trusts others wholeheartedly, keeps making mistakes at work and ends up being sent to work in an insignificant position while Watabe plays Chajima Ryunosuke who is a lawyer with no morals and doesn't believe in people. The two of them who are 24 years apart in age, form an unlikely alliance to crack unresolved cases in the Mikaiketsu Jiken Tokumei Koshoka by using plea deals to get suspects and the accused to testify against the true culprits responsible for committing the crimes.

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 cases by offering leniency to suspects for information on the main culprits. Ryunosuke Chajima is himself a devious attorney. Why he takes part in the Cold Case Anonymous Investigation Unit is unknown.