Tasked with joining a temporary mobile investigation unit, Kazumi Shima gains a new partner in Ai Ibuki, an officer with a troubled past.

After Ibuki senses something odd about a passing car, his suspicions are confirmed when he hears over police radio about a murder suspect on the run.

When the police have trouble catching the perpetrator of a series of prank calls, Ibuki boldly proclaims that nobody is fast enough to outrun him.

A shooting incident leads Shima and Ibuki to go in search of the victim, who they soon learn is carrying a huge sum of cash and has a criminal record.

Ibuki and Shima go undercover as convenience store clerks to prevent a robbery. However, their plan hits a snag when more than one store is targeted.

Having overheard someone call Shima a partner killer, Ibuki begins to probe into Shima’s past in a bid to uncover the secret he’s hiding from him.

After investigating a body believed to be related to an unsolved serial murder case, Ibuki discovers that his mentor arrested the victim years prior.

Kikyo learns that the Tatsui gang is responsible for planting the bug in her house. Kokonoe resolves to catch Narikawa before he commits more crimes.

The MIU discovers that Etori was taking orders from a mysterious youth. Suspecting that Kuzumi is the culprit, Shima and his team set out to find him.

With Jinba in a coma and the MIU on the verge of falling apart, Shima and Ibuki grow distant and begin to take matters into their own hands.