Who is Mukai—the mysterious man from headquarters dispensing spot-on advice to struggling young detectives?

A groundbreaking vision for police procedurals!

Mukai, an enigmatic mentor sent from headquarters, appears before promising young detectives whose careers have hit a wall. Among his pupils: one haunted by a blunder during an investigation, another struggling to interrogate a high-profile actor, and a third who simply cannot master the art of tailing a suspect.

Though Mukai offers precisely the advice each detective needs to succeed, a puzzling question lingers: why is a man of his extraordinary talents assigned to Personnel rather than the Criminal Investigation Division?

When the three detectives eventually grow into seasoned investigators and return to headquarters, a new case intersects unexpectedly with Mukai's past—compelling them to start digging into the truth behind their former mentor.