Inukai Tsuru (Taira Yuna) and Saruwatari Hibiki (Maruyama Ryuhei) begin a reinvestigation of the Taikoji Temple murder case from seven years ago. The victim was Chono Yasunari (Tajima Ryo), a reporter for a notorious gossip weekly magazine. While listening to the stories of those involved, including professional boxer Kumada Hiroki (Sano Gaku), who was the first to discover the body, and Hachiya Mitsuru (Holiday Section Chief), the son of the temple's head priest (Rokupei Naomasa), who runs a Thai restaurant, Tsuru senses something is amiss. At Tsuru's suggestion, they begin undercover investigations at the boxing gym and the Thai restaurant, and the two begin to gradually get closer to the heart of the case...

Inukai Akari (Taira Yuna) and Saruwatari Hibiki (Maruyama Ryuhei) continue their investigation into an unsolved murder that took place at a temple seven years ago. The key to the case lies in traces of perfume left on the victim's clothing. With Akari's genius sense of smell and memory and Saruwatari's bold action, they discover a clue that connects the victim to professional boxer Kumada Hiroki (Sano Gaku) and the head priest's (Rokupei Naomasa) son, Hachiya Mitsuru (Holiday Section Chief). Akari discovers a secret that Kumada and Hachiya are trying to hide... What is the heartbreaking truth behind the case?

Mikan receives an email from Toru Makami (Takayuki Hamatsu), a video streamer of supernatural stories, requesting that they investigate the mysterious death of a high school girl that occurred six years ago. It is said that the ghost of the deceased high school girl haunts the school... Sukui (Yuna Taira) is enthusiastic, but for some reason Saruwatari (Ryuhei Maruyama) refuses to investigate. Sukui goes alone to question Kobayashi Tanukiko (Nozomi Miyabe), a friend of the deceased Usami Aiko. Meanwhile, Saruwatari learns of an unsolved case... When Sukui returns to Mikan's room looking tired, Saruwatari...

Inukai Tsuru (Taira Yuna) and Saruwatari Hibiki (Maruyama Ryuhei) infiltrate the abandoned school where a high school girl fell to her death and try to uncover the mystery of the ghost. They discover that the ghosts are the deceased Usami Aiko and her online gaming friend Inari Nozomi (Nakamura Yurika). Nozomi learned of Aiko's death on the news and had been pretending to be a ghost in order to find out the truth. Furthermore, Tsuru witnesses another person on the roof of the abandoned school. From the footage filmed by Makami Toru (Hamatsu Takayuki), he realizes the true identity of the figure he witnessed...

Having regained her confidence after solving numerous cases together with Saruwatari (Maruyama Ryuhei), Sukui (Taira Yuna) has finally decided to return to her job as a police officer. At a celebration for her return, Sukui confides in Saruwatari that she wants to investigate the Yanaka Child Murders, the last unsolved case investigated by her father, Inukai Jūshiro (Yamaguchi Makiya), who died in the line of duty. The key to the case lies with Kito Yasuomi (Takahashi Katsunori), Jūshiro's former partner and head of the Metropolitan Police Department's First Investigative Division. Saruwatari and Sukui go to meet Kito at the Metropolitan Police Department, but...

While pursuing the criminal, Sukui (Taira Yuna) is stabbed, and although her life is not in danger, Saruwatari (Maruyama Ryuhei) is tormented by feelings of guilt. Sukui, who suffers from prosopagnosia, is unable to recognize the criminal's face, loses confidence again, and gives up on returning to his job as a police officer. Masato (Fukuyama Shota), who cannot forgive Saruwatari for hurting Sukui, promises Saruwatari that he will never see Sukui again. The Mikan Room is also suddenly ordered to be demolished, and the members are scattered... One year later, Saruwatari receives a call from a certain person.

Sui (Taira Yuna) tells Saruwatari Hibiki (Maruyama Ryuhei) that the perpetrator of the child murder case is someone the two of them had seen in a used bookstore in the past. However, Saruwatari, regretting having injured Sui, pushes away Sui's desperate pleas to resume the investigation. Unable to give up, Sui calls out to Ushio (Kajiwara Zen) and Hyotou (Yamura Rintaro), and the three of them reunite in Mikan's room and plan to infiltrate the Metropolitan Police Department in order to obtain the notebook left behind by Sui's late father, Inukai Jushiro (Yamaguchi Makiya).

As Suki (Taira Yuna) tries to look up the Yanaka Police Station list in Mikan's room, the culprit closes in on her. Suki realizes the culprit's true identity, but ends up being caught by the culprit. Meanwhile, Saruwatari (Maruyama Ryuhei) hears a voicemail from Suki left on his cell phone and heads to Mikan's room, but Suki is not there and instead sees a suspicious man carrying a large cardboard box. Will Saruwatari be able to save Suki with his detective instincts and ability to act? And will the two be able to solve this fateful case?