Keiji Higashino/History

Chapter 7
He arrives at Saga walking down a deserted road and exclaiming how empty Saga is, then he arrives at Karatsu where Anna sees him at the city station wandering around and with a distraction for Eikichi, decides to follow him to see what he is doing in Saga until that he finally realizes and manages to learn Anna by surprising her from behind. In a dark alley in Saga, he tells her about some past events and doubts Anna's "righteous" actions currently thinking that she went crazy with her stories about supernatural beings in Saga until he sees his first Sagako scaring him. to the point of pulling out his gun and taking advantage of the fact that Anna is distracted by his shots, he immobilizes her with his gun behind her back, demanding some answers about her.

Chapter 8
He has his first encounter with Anna by catching her shoplifting on the street. In the interrogation Keiji talks with her about her family and how he could send her to a prosecutor to analyze her case, but instead of that, he decides to team up with Anna to catch and detect robberies in Tokyo. With Anna's help he makes himself known as someone of importance to the Tokyo police.

One day, Anna sniffed out a great 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 in reinforcements to control the situation, obviously the criminals didn't see it coming and it was pure chaos with the result that many people died that day. Anna disappeared shortly after the incident and years later he would find her in Saga. In the present, he is still chasing after the first Sagako he encountered and shoots it one last time before it vanishes, thinking that he 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 over his actions, Araki Aiba. After asking the rookie cop a few questions he tells him that the Sagakos are a real thing and they are monsters that terrorize Saga, Aiba only replies that he knows of a group that deals with supernatural things in Saga, the Sagako Busters. Despite knowing that there are creatures in Saga, he wants to know that they can offer these to the humans as he would allow the humans to win this battle.

Higashino begins to investigate the sightings of Sagako and comes to the quick conclusion that they appear in populated or prosperous areas, therefore, he himself goes to one of these areas, not without first being approached by Aiba who 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 guides him to a forest where they both meet a crowd of Sagakos in that area and Higashino begins to observe them carefully, seeing how one of them seems to be crying tears of acid or poison that destroys the grass around it to which the detective only comments that they could use it as fertilizer and sell it to the agricultural industry. To make a closer inspection of the Sagako, Keiji tries to open it 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, attracting the attention of Eikichi who was hanging around the area while he rejoices at the pain he just caused the Sagakos. Eikichi is speechless seeing the dead and unpurified Sagakos and confronts Higashino about what he did, Keiji wastes no time and punches the high school boy leaving him on the floor and insulting the entire legacy of the Sagako Busters group by calling the group false heroines of justice who think they help the world. Higashino leaves the place while Aiba tries to calm him down a bit about the situation.

Chapter 10
The questions that Higashino has about the Sagakos continue, finding himself on a mysterious beach he seems to be planning something, Araki who is behind him asks him what they are doing there, not very confident that carrying a Sagako in a fish tank is something safe. Keiji acted in a mysterious way that morning by capturing that Sagako and taking him to the beach, but before continuing with what he was thinking, he leaves the task to Araki of caring for and raising the Sagako that he has in his hands. Mainly because the day before he lost his sanity and killed all the other Sagakos they had found, so he must not lose his sanity this time, Araki is shocked by what he is saying, but more on the side that his Residential complex does not allow pets. Finally with Araki agreeing, he promises to leave food and water for him to take care of. 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 shows no change despite not having eaten or drunk water, which further uncovers Higashino's curiosity who wonders if it is a conventional living being or a truly supernatural being. While wondering the true source of the Sagako's energy, 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 was previously and proceeds to perform the experiment he was thinking about days ago. He explains to Araki that the rock ahead is called of them is Tsutsumiichi, a border between the former Hizen prefectures and the Chukuzen provinces, or in other words, the border with Fukoka.

Higashino throws the Sagako across the border and as soon as it crosses it starts to bubble and explodes as a black mass as the remains of it fall to the ground, shocked, Araki quickly leaves the place while Higashino remains undeterred. Suddenly something happens that leaves him dizzy, in front of him appears a mysterious figure of a girl with a demon mask who reveals some questions that he had previously and presents himself as part of the God Magatsuhi. Understandably taken aback, Higashino can't believe how many strange things he's been living with since he came to Saga, Magatsuhi thanks him for eliminating that Sagako and makes a deal with him that if he eliminates all the Sagakos from Saga, he will receive a "prize" and the original power of Magatsuhi will return.

Chapter 11
It has been 2 weeks since he made the deal with Magatsuhi and he continues to kill Sagakos, he still has doubts about how Sagakos work since their bodies disappear when they die, he begins 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 telepathically with him, but he seems to be angry with her since apparently she will not fulfill his wish despite the fact that he has already killed hundreds of Sagakos so that nothing is reached. Keiji is clouded with anger at the fake deal and points his gun right at Magatsuhi, yelling at the top of his lungs wanting power from him.

Before shooting, he is pierced by one of Magatsuhi's limbs and thrown against the pavement of the street. Before dying, Higahino 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/Sipnosis