A serial murder case broke out in Wangye Town in 2008. Kiryu Aoi lost her family, friends and love, and her father became a suspect and was arrested.Sixteen years later, detective Aoi returned to her hometown to investigate the truth and discovered that her classmate might be a suspect, while her partner Kei Kasaka was monitoring and suspecting Aoi.During the investigation, she revealed the truth about her classmates and Hui's past, as well as the connection between the two incidents.Then, a truth that had been hidden for 16 years came to light.

The promising detective Kiryu Aoi realizes her long-cherished wish and takes a job at the police station in Yonomachi, a suburb of Tokyo.Aoi's partner, Kei Kasaka, a detective at the Nozomi Department, was puzzled as to why she came to the Nozomi Department and began to investigate.

Yono Town is Aoi's hometown and the place where two murders occurred 16 years ago.The victims in that case were all young women, and their bodies had their mouths filled with marbles.Aoi, who was still a high school student at the time, discovered the body of the younger sister of her favorite classmate Sho Fuwa.Aoi was so shocked that she lost her memory before she found the body.

Soon, Aoi's father was arrested as a serial murderer and died of illness in the detention center.Aoi, who became the daughter of a vicious criminal, left the city.

Sixteen years later, Aoi, who believed her father was innocent, returned to Mochino Town in order to explore the truth of the incident.

Aoi reunites with Megumi Oto, Yuki Amakusa, and Momo Asuka, who are also classmates in the Image Research Department.Another partner, Fu Po, disappeared after the incident 16 years ago.

At this moment, the Wangye Police Station received news that the female high school student was missing.Kento Ichijo led the members of the Hope Field Office to go together.Then Aoi and Kasaka discovered a marble similar to that incident.On the other hand, Kosaka's former boss Takeshi Arimura issued an order to Kosaka to monitor Aoi.

Around WangyeTownTaking the new incident as an opportunity, Aoi continues to search for the real culprit of the serial murders, and, toOver the past 16 years, thisTownThe hidden truth challenges——!

Aoi discovers the body of Umezaki Wakana who came to Mochino Town for sightseeing.The body's mouth was filled with marbles.Led by Kasaka, everyone in the first department was searched and thought to be the imitator of the incident 16 years ago.But Aoi countered that the incident 16 years ago was a false accusation, and it was possible that the real culprit of the murder had not yet been caught.

At the same time, Aoi heard the truth about 16 years ago from Megumi, Amakusa, Momo and other partners in the Image Research Department.

Later, it was discovered that a man left the area immediately after Umezaki Wakana was killed.The look in the surveillance video looks very similar to Bupo.The investigation will be conducted under the sign of no breach.Aoi applied to the section chief, Taketo Ichijo, saying that she wanted to investigate the connection between Fuya and Wakana..

Ichijo allows Aoi to investigate, but only if he cooperates with Kasaka.As Aoi and Kasaka's investigation progresses, their suspicion of Fuwa grows stronger...!?

Aoi began to think about the truth behind the murder of Umezaki Wakana, and the true intention of admitting that the serial murderer 16 years ago was her.

In the process of hunting down Fuha who escaped during the first search, Fuha's confession was captured on video and spread on the Internet.Wangye Police Station received a large number of media who came to confirm the authenticity of the unbreakable confession.Aoi arbitrarily announced to reporters that she would re-investigate the incident 16 years ago.

Regarding Aoi's “rage”, Kosaka and other members of the Search First Department expressed their opposition.Aoi proposed to Ichijo that she wanted to investigate the incident 16 years ago, and Ichijo agreed.

While Aoi was investigating the investigation data at that time, Kasaka used a monitor to monitor Aoi's every move.Aoi discovered that important testimony materials proving the suspicion of her father Yasuo, who was arrested for the incident 16 years ago, were missing.

Kizaki and Natsume asked Amakusa, who assisted Fuwa in his escape, about the situation, but Amakusa denied that he was an accomplice.

Aoi and Kasaka went to the bar where Wakana frequented.According to the bar owner, Fuha and Wakana often come to the bar together.Then, Fupo told Wakana that I killed my sister... Aoi and Kasaka knew it.

Even so, Aoi doesn't think this is a crime that cannot be broken or established.After listening to Aoi's reasoning, Kasaka told Aoi something unexpected -.

Together with Kosaka, Aoi questioned Oto Makoto who met her on the day Wakana was killed.Megumi saw the tense look between Aoi and Oto.

Later, Megumi told Aoi the truth about when Fupo Sho's sister was murdered 16 years ago.Aoi also learned from Tao that Ling was entangled by Aoi's father Kang Nan 16 years ago.Aoi has doubts about her father, whom she has always trusted, and falls into chaos.

On the other hand, the murder of Umezaki Wakana was determined to be a culprit, and the search was decided to end.Aoi asked if it was the judgment of the superiors, but was retorted that it was a matter of decision.

Aoi came to Hui's house and wanted to ask about her father again.While the two were talking, Hui's daughter Shibu disappeared.Just as Aoi and Megumi were desperately searching for Shibu, they received a threatening call from the prisoner who kidnapped Shibu.The murderer's request to Hui is to tell your family, confess the truth about the serial murder case 16 years ago, and apologize... A new incident occurred.

Aoi, who saw the body of Oto who died in the detention center, had a flashback to the time when she found the body of Fuwa Sho's sister 16 years ago.

The Mochino Police Station Investigation Department 1 is conducting a search for the criminal who kidnapped Megumi's daughter.At the request of the abductor, Kosaka claimed that he was a person related to the incident 16 years ago.

Aoi asks Bupo if anyone else knows the secret code that only we know.Bupo replied that his sister Ling knew the secret code.Aoi borrows Ling's relics from Bupo to investigate.Just then, Aoi remembered something.

The unpublished eyewitness testimony from 16 years ago may be false. After the media found out about it, it was also reported on the news.There are even reports that the daughter of a serial murderer from 16 years ago assumed her identity and became a police officer.An order for Aoi to remain in home confinement until the situation stabilizes...

At the same murder place as 16 years ago, Aoi found the body of a woman with marbles stuffed in her mouth, and was convinced that the serial killings had begun again.Then, the Wangye Police Station established the “Serial Murder Investigation Headquarters”.

In the first search department, Yabuki from the Metropolitan Police Department was appointed instead of Ichijo.

The new victim is 18-year-old Ruri Wada who lived in Mokino Town half a year ago.The prisoner who killed Liuli is likely to be the same person as the prisoner in the serial murder case 16 years ago. The police launched an investigation based on this.

Kasaka hinted that the prisoner may have other victims.But Yabuki told Kasaka not to have unnecessary thoughts because it was for herself.Aoi feels strange about the relationship between Kasaka and Yabuki.

According to Ruri's call records, it was found that the last people she called were Momo, Aoi and Kosaka, and they investigated Momo's situation.Tao replied: "Liu Li is one of the guests, I don't know very well."%But Aoi felt strange about Tao's words and deeds and continued to ask.

At the same time, Wangye Police Station received an anonymous report about the serial murder case.Aoi and the others rushed to the place where the police were called...!

Aoi and Kosaka investigate Amakusa, the cellphone owner of the new victim Wada Ruri.Amakusa explained that Ruri's cell phone was found in his taxi.

Kasaka noticed something about the victim that hinted at new possibilities.The investigation headquarters began to track the suspicious person Amakusa.

Kasaka also told Aoi that the reason why the murderer triggered the serial killings may be related to Aoi.Aoi felt that she might have taken away the lives of many unrelated people, and her heart was a little shaken.

On the other hand, Aoi heard unexpected facts about a movie script she wrote 16 years ago from Bupo.

Under such circumstances, Kosaka obtained new information from Wada Ruri's mobile phone and went to the Metropolitan Police Headquarters. The incident developed in an unexpected direction——

Aoi witnessed Kosaka pursuing Amakusa.

Amakusa said that the person who killed Kosaka's junior detective Aso was not him, but maybe the senior of a special fraud group who killed “ the detective”.

Aoi was worried that Kosaka would pursue Aso's murderer alone, so she sent Natsume to monitor Kosaka.Kosaka decided to risk everything to find out the truth about Aso's death.

Aoi left a note at the scene of the serial murder case, which contained a coded message for the murderer.Aoi originally planned to use herself as bait to lure the murderer to her.

Based on information from Amakusa, Kosaka arrested Sakai, a member of the special fraud group.Sakai said that he only heard rumors that a man who called himself “Hulk” said “killed the detective”.

On the other hand, Fuwa visits Ide, a classmate of the high school culture festival executive committee and a grocery store owner.

Aoi goes to the crime scene and confirms that the message left behind is gone.Someone is following Aoi who left there——!?

Aoi searches the grocery store run by Ide, a serial murderer who surrendered.There was enough evidence to prove Ide's crime.During the investigation, Ide confessed to all crimes.

Although Aoi and Ide are high school classmates, they can't think of anything to do with him.

The serial murderer's motive is believed to be his obsession with Aoi, but the reason for his obsession with Aoi is unknown.

Aoi began to investigate Ide and asked him about the reason for his obsession with her.

On the other hand, Kosaka and his son Jun hunt down the escaped Arimura.Arimura and Jun are hiding somewhere….

Ide stated the details of the incident, but his obsession with Aoi was incomprehensible.Then, Kasaka began to investigate Ide.Ide suddenly came up with a puzzle, which confused Aoi, Kasaka and the others.

Aoi discovers conclusive evidence against the real murderer in Ide's grocery store.

At this time, one of her classmates, Asuka Momo, appeared in front of Aoi.After learning the real culprit of the serial murder, Aoi was shocked.Tao admitted that all the murders were committed by himself.Aoi was pinned down by Tao on the electric shock rod and lost consciousness.

Kasaka was listening to the conversation between Aoi and the real murderer through Aoi's smartphone, which was in a call state. Suddenly the sound was interrupted and he noticed something abnormal happened to Aoi.When Kizaki and Natsume rushed to Ide's grocery store, Aoi had already been taken away.Kosaka called Ide, who was sent to the Metropolitan Police Headquarters, back to the Field Office to ask for clues about where Momo abducted Aoi.

Aoi wakes up and confronts Tao while being restrained.

What is the agreement that Tao told Aoi about 16 years ago? What is the truth of the 16th year that Aoi is pursuing?