The Recording, Shima’s Testimony, and the Arrest of the Sekines

The recordings, Shima’s testimony, and the arrests of Gen Sekine and his wife transformed a stalled investigation into the resolution of the Saitama Dog Lover Serial Disappearances case. The tapes did not provide a clean confession or an immediate answer. Their importance lay in the leads they opened: a chain of information running from Kimiko, through Ryoji Arai and Shima, to Sekiguchi and the police, with Takada’s pursuit helping bring Shima back into reach.

A lead from Kimiko

On September 2, while Jake Adelstein was in a love hotel in Omiya with Kimiko, she suggested that the police obtain Arai’s tapes. She had heard about them from a yakuza regular at her bar, who said Arai had boasted that he possessed evidence against Sekine. As Kimiko relayed it, Arai believed the recordings showed Sekine admitting to the murders and would protect him from the fate of Yasunobu Endo. The account also implicated Shima, Sekine’s driver, in the disposal of Endo’s body. This was information passed through several people, not material Adelstein had heard himself, but it was specific enough to change the direction of the inquiry.

Sekiguchi initially faced a dilemma. If he passed the information directly to Takada, Takada might find Arai, obtain the tapes by force, and kill both Arai and Sekine. A suspicion that Sekine had killed Endo was not the same as having his admission recorded; the tapes could make the accusation more consequential while also putting the people involved in immediate danger. Sekiguchi therefore took the lead to Takada’s second-in-command, referred to as the Consigliere, who said he would handle it quietly.

Arai’s account changes the inquiry

The Consigliere found Arai, who became willing to talk. He did not initially tell Takada about the tapes, and Arai’s revelations altered the investigation’s focus. According to Arai, he had not been involved in the disappearance of the last four victims. Instead, he had learned from Shima that Sekine had killed Endo and Endo’s driver, Wakui, with poison, and that Shima had helped bury them. The account made Shima central: what he knew could connect Sekine to Endo’s death.

Police arrested Arai on a fraud charge. They regarded a possible confession to his wife’s murder as difficult to prove after ten years without a body; their immediate interest was what he could tell them about Shima. The investigators hoped that if they could get Shima to speak, Sekine would become easier to prosecute. The tapes, meanwhile, remained a precarious source of corroboration rather than a self-sufficient case. Their existence had set events in motion, but the investigation still depended on finding and questioning Shima.

The arrangement with the Consigliere did not keep the tapes secret from Takada. On the day Arai was arrested, the Consigliere told his boss. Takada then called Shima and demanded that he disclose where Endo’s body was, threatening that Shima himself might otherwise need a burial place. Shima was shaken, but the demand put him in an impossible position: as he understood it, there was no intact body left to locate after its destruction. Takada wanted justice for Endo and a case strong enough for Sekiguchi to pursue, but he was also trying to force the investigation forward.

Shima disappears, then returns

Takada promised Sekiguchi that he would not kill Shima, saying that Sekine mattered more while he remained free. He also wanted time alone with Shima, and asked whether the police could withdraw their watch on Shima’s home. Sekiguchi could not officially do so, but his repeated qualification that officers were there only most of the time conveyed an opening. When the watch was absent, Takada and several men arrived. Seeing them, Shima escaped through the back and ran to the police station. He fell to his hands and knees and begged the police to guard his home around the clock.

The police could not promise continuous protection. Shima fled, and no one—not Takada, Sekiguchi, or the Saitama police—knew where he had gone. Arai was in custody, but the inquiry again stalled. At this point the Consigliere passed several audio tapes to Sekiguchi through the unusual information network that had helped him navigate both police and yakuza circles. The recordings were poor in sound quality and included coded exchanges. They did not contain anything plainly damning, but investigators could make use of what was audible in an interrogation room. They still needed Shima: without him, there would be no effective questioning and no case to build.

Testimony and closure

In November, Sekiguchi left the team and returned to the Anti–Organized Crime Division. The prevailing assumption was that Shima had been killed and that the investigation would remain unsolved. Takada continued searching. In late November, he found Shima, who had changed his name and married, and passed the information to Sekiguchi, who relayed it to the Saitama police. They arrested Shima in December. Confronted with the existence of the tapes, Shima spoke to investigators.

Shima directed police to a site in Gunma Prefecture. There, they found enough of Akio Kawasaki’s teeth to support their case. The search was conducted by a very small crew, and the Yomiuri and other outlets did not know it was happening. The discovery supplied physical evidence where the investigation had repeatedly confronted the absence of bodies, while Shima’s account connected that evidence to the people under investigation.

On January 5, immediately after the New Year’s holidays, the Saitama police released Shima on bail and announced the arrests of Gen Sekine and his wife, Hiroko, for the dismemberment of Kawasaki. Within hours of his arrest, Sekine admitted almost everything. After an agonizing year—and, in one sense, more than a decade—the case was closed. The sequence gives the recordings their particular significance: they were not a single decisive proof, but the point from which testimony, a concealed burial site, and finally an admission could be brought together.