When Natsumi's body is found over two years after her disappearance, her husband Riku embarks on a dangerous search for her killer.
Hoping to avoid a confrontation with businessman Goroku, Riku faces a brutal dilemma: catch a thief who stole 1 billion yen or face lethal consequences.
Riku and Ichika uncover a new suspect in the 1-billion-yen case and meet Gido's wife, whose presence quickly draws the attention of other detectives.
Another theft hits Goroku, but there may be video of the culprit. At Mayu's insistence, Riku travels to the mountains to try and learn the truth.
Riku and Ichika find a new motivation to crack the case after they team up to tail the real Gido, who accidentally leads them to a criminal cabal.
After the police make an arrest in the case, Gido contacts Riku, desperate for his help in exposing the real culprits behind the 1 billion-yen theft.
Now that it's too late for Riku to return to his old life, he investigates the murder of one of Goroku's clients with a personal connection to Fuyuhashi.
Desperate and erratic, Riku enlists Fuyuhashi's help in manipulating a hospitalized Ayaka to develop a lead on the still-missing Ichika.
Riku attempts a daring rescue and sets his sights on destroying Goroku's criminal empire, even if it puts his life in grave danger.
As Goroku's final plan unfolds with 10 billion yen en route, Riku uncovers the truth behind Natsumi's disappearance two years ago.