Yugami and Hanyu investigate the brutal attack on Sergeant Masashita, a beloved officer found unconscious in the mountains just before his retirement. As they uncover clues involving a mysterious sketchbook and a suspicious man seen at the hospital, Hanyu vows to catch the culprit responsible for harming his respected mentor.

Yugami and Hanyu investigate the suspicious death of an architect who fell from an unfinished building. The investigation reveals a love triangle involving the victim, his fiancée, and a colleague who claims self-defense during a confrontation. The case takes a personal turn when it’s discovered that Hanyu had previously dismissed the victim’s earlier stalking complaint.

A kidnapping case involving the daughter of a prominent family is marked by a symbol linked to a past murder inspired by a sinister novel. The author of that novel, who used the same symbol, was once apprehended by Yugami. As the investigation deepens, old connections resurface, leading to a tense ransom demand that forces the detectives to unravel the mystery.

A wealthy former doctor is found brutally murdered in his home, with a cryptic note suggesting revenge as the motive. Despite the eerie similarities to a crime depicted in an unfinished novel by a notorious criminal, Yugami remains oddly uninterested, even as the team pursues the case, suspecting the doctor’s long-lost son might be involved.

Yugami mysteriously vanishes after visiting a hospital where Hizumi is in a coma. Meanwhile, Hanyu and the team discover that the supposed dead author, who was responsible for the murders years ago, may still be alive and behind recent crimes.

Detective Yugami, a quirky and unconventional investigator, partners with the ambitious rookie Hanyu to solve the suspicious death of a female college student, uncovering a web of secrets involving harassment and a mysterious suspect.

Yugami and Hanyu investigate an attempted rape case involving a middle school teacher, Chisato, who was attacked in her apartment. Although Chisato refuses to cooperate, the detectives discover a connection between her and a student, leading to the identification of a suspect through clues left at the scene.

A wealthy young IT entrepreneur is attacked at a planetarium after posting about his visit online. The victim, known for aggressive business tactics, has many enemies, including a telescope maker whose company he drove to bankruptcy. As the detectives investigate, they uncover a web of resentment and business rivalries, leading them to suspect a connection with a popular game app and its creator.

The detectives investigate the poisoning death of Sugano's friend, Eriko, who was found dead shortly after a reunion. Despite her seemingly happy life, it’s revealed that she was struggling with a demotion and had secretly left her job months earlier. As they dig deeper, they uncover a hidden relationship and a dark secret that complicates the case.

Yugami, feeling down about his favorite racehorse's retirement, takes Hanyu to a nightclub where they encounter a former thief, now trying to live an honest life. A few days later, she is found dead with a large sum of money, and her death is deemed an accident. However, Yugami suspects foul play due to her past skills and a promise she made to him. Meanwhile, the team is drawn into a fraud investigation targeting the elderly, where an unexpected connection to the woman’s death emerges.