Keiji Higashino/History

Chapter 7
He arrives at Saga, walking down a road and exclaiming how empty Saga is. Afterwards, he arrives in Karatsu, where Anna sees him at the city station. Anna distracts Eikichi while she goes to track him down to see what he's up to in Saga. The two finally meet and Higashino grabs Anna, surprising her from behind. In a dark alley in Saga, he tells her about some past events and doubts Anna's “righteous” actions, thinking that she has gone crazy with her stories about supernatural beings in Saga. Or so he believed, until he sees his first Sagako firsthand, scaring him to the point of pulling out his weapon. Taking advantage of Anna being distracted by her shooting, he pins her down with her gun to her back, demanding some answers from her.

Chapter 8
He has his first encounter with Anna by catching her shoplifting on the street. In the interrogation room, Keiji tells her about her family and how he could send a prosecutor to investigate her case, but instead he decides to join Anna in catching and detecting robberies in Tokyo. With Anna's help, he establishes himself as someone important to the Tokyo police.

One day, Anna sniffs out a grand plan made by a group of thieves and when the day was ready, she told Higashino. The operation was so big that Keiji had to call reinforcements to control the situation, obviously the criminals didn't see it coming, and it was pure chaos. As a result, many people died that day. Anna disappeared shortly after the incident, and years later he would find her in Saga.

In the present, she is still chasing the first Sagako she encountered and shoots him one last time before he vanishes, thinking that she could take them out with guns.

Chapter 9
After being intervened for his excess of freedom by the Saga police, he will now have a partner to watch his actions, Araki Aiba. After asking the rookie cop a few questions, he tells him that the Sagakos are real and are monsters that terrorize Saga. Aiba only answers that he knows of a group that deals with supernatural things in Saga, the Sagako Busters. Despite knowing that creatures exist in Saga, he wants to know what they can offer these to humans because it would allow humans to win this battle.

Higashino begins to investigate the sightings of Sagako and quickly concludes that these appear in populated or affluent areas; thus he heads to one of these areas himself. Aiba approaches him because he must watch him to avoid a scolding from his boss. Before leaving, Higashino tells him to guide him to a popular area or one that will be prosperous in the future, to which the policeman leads him into a forest. They both come across a crowd of Sagakos in that area, and Higashino begins to watch them carefully, seeing how one of them seems to be crying tears of acid that destroys the surrounding grass. The detective only comments that they could use it as fertilizer and sell it to the agricultural industry. To get a closer inspection of the Sagako, Keiji tries to open him using a stone, but is hit by the Sagako he was trying to hurt, to which he responds by shooting all the Sagakos in the area. This attracts the attention of Eikichi, who was hanging around the area, while he rejoices in the pain he just caused the Sagakos.

Eikichi is speechless seeing the dead Sagakos and confronts Higashino about what he did. Keiji gets mad at him and ends up beating him while he's on the ground and insulting the entire legacy of the Sagako Busters group by calling the group fake heroines of justice who think they're helping the world. Higashino leaves the place while Aiba tries to calm him down a bit about the situation.

Chapter 10
Higashino's questions about the Sagakos continue. Araki, who is behind him, asks what they are doing there, since it doesn't seem very safe to keep a Sagako in a fish tank. Keiji acts mysteriously that morning by capturing that Sagako and bringing him to the beach. Before continuing with what he was thinking, he leaves it to Araki to take care of and raise the Sagako that he has in his hands. This because the day before, he lost his sanity and killed all the other Sagakos that he had found; therefore, he shouldn't lose his sanity this time. Araki is surprised by what he's saying, but more on the side that his complex doesn't allow pets.

Araki agrees, and Higashino promises to leave food and water for Doro-chan. The following days, he fulfills his promise by leaving Araki enough food and water for the Sagako to survive. After several days with Doro-chan, the Sagako still doesn't show any change, despite not having eaten or drunk. This further uncovers Higashino's curiosity, who wonders if he is a conventional living being or a truly supernatural being. As he wonders the true source of the Sagako's power, he remembers what Anna told him earlier, that the Sagakos are the symbol of the end of Saga. Remembering this, he returns to the beach where he previously was and proceeds to carry out the experiment he was thinking about days ago. He explains to Araki that the rock they see ahead is called Tsutsumiichi, being a border between the former Hizen prefectures and the Chukuzen provinces. In other words, the border with Fukoka.

Higashino throws the Sagako across the border and as soon as it crosses it begins to bubble and explode as a black mass as its remains fall to the ground. Shocked, Araki quickly leaves the place, while Higashino remains unfazed. Suddenly something happens to him that leaves him stunned. In front of Higashino appears a mysterious figure of a girl with a demon mask, who reveals some questions that he had previously and introduces herself as Magatsuhi. Understandably bewildered, Higashino can't believe how many strange things he's been living with ever since he came to Saga. Magatsuhi thanks him for eliminating that Sagako and makes a deal that if he eliminates all of Saga's Sagako, he will receive a “reward” and Magatsuhi's original power will return.

Chapter 11
It's been 2 weeks since he made the deal with Magatsuhi, and he's still killing Sagakos. He still has doubts about how Sagakos work because their bodies disappear when they die. He starts to feel dizzy and hears Magatsuhi's voice saying that she has already regained her power. Arriving where Magatsuhi is, he asks her to fulfill his wish. Magatsuhi communicates with him telepathically, but he seems to be angry with her, since she apparently won't fulfill his wish even though he has already killed hundreds of Sagakos to come to nothing. Keiji is clouded with anger at the false deal and points his gun straight at Magatsuhi, screaming at the top of his lungs his desire for power.

Before firing, he is impaled by one of Magatsuhi's limbs and thrown onto the street pavement. About to die, Higashino remembers his life and all the most relevant moments of it, while Magatsuhi tells him that if he had power, he could do whatever he wanted. In his last moments, Higashino realizes that he was only used by this creature. Keiji Higashino/Historia