Gen Sekine and Ryoji Arai’s business partnership

Gen Sekine and Ryoji Arai’s business partnership began in the animal trade and became consequential when their deteriorating association intersected with investigations into missing people and suspected killings. Arai had worked as the African Kennel’s public-relations representative and was described as Sekine’s business partner; after the two fell out, information tied to their shared past helped shift the investigation toward Shima and Sekine.

The Partnership and Its Business Setting

Arai and Sekine had known each other for roughly a decade. Sekine’s history in business stretched back to 1972, when he began dealing in exotic pets. The trade prospered, and he later settled in Kumagaya, where he married another animal lover. He also made pet food himself, a detail that places the partnership in a practical animal-business world rather than a merely social connection.

Arai’s position at the African Kennel connected him directly to that enterprise: until shortly before the reporting, he had served as its public-relations representative. The available account does not specify the partnership’s formal terms or divide its responsibilities in detail. It does establish that the two worked together in business and that Arai’s knowledge of Sekine’s affairs later made their former closeness relevant to the investigation.

Arai’s Debts and Disappearance from the Scene

The partnership existed alongside Arai’s separate and increasingly dangerous dealings. According to Sekiguchi’s account, Arai sold an expensive dog to a Sumiyoshi-kai group leader and was supposed to care for it while the leader traveled. Instead, Arai abandoned the dog and left town with money borrowed from the group to establish an animal-import business. He had also allegedly taken a couple of million yen borrowed from Takada.

The abandoned dog and missing money provoked the Sumiyoshi leader, who vowed to pursue Arai. Arai then withdrew to a remote area, changed his name, adopted religion, and took up Buddhist painting. Years later, he reappeared and seemed to be working with Sekine again. The account suggests that Sekine’s success may have drawn him back, but presents that explanation as speculation, not established motive. His renewed association was brief: soon afterward, Arai vanished from view, and investigators suspected he might know something about the disappearances around Sekine.

The Rupture and the Missing-Wife Suspicion

The partnership eventually broke down. Reporting at the time placed Arai’s wife’s disappearance before the falling-out. The narrator suspected that Arai had killed her and that Sekine had helped dispose of her body, but this was an inference, not a proven finding. The distinction matters: the book records a suspicion arising from the sequence of events, not a confirmed account of what happened to her.

Arai was also wanted in connection with conflicts involving major crime groups. A police contact reported that he had antagonized both the Inagawa-kai and the Sumiyoshi-kai: in one case through harm to a member’s dog, and in another by taking a large amount of money. A zetsuenjo circulated in Arai’s name. Unlike a notice simply announcing separation from an organization, this kind of document marked someone as a betrayer, excluded him from membership, and could solicit information about his whereabouts. Arai’s exposure to these groups’ hostility made his renewed work with Sekine—and his later disappearance—especially significant.

From Former Partner to Investigative Witness

The investigation’s direction changed when Arai was found and became willing to talk. Before that, Kimiko had relayed a report that Arai had told a yakuza acquaintance he possessed tapes implicating Sekine in murders. In that account, Arai claimed the recordings made him safe from the fate of Endo, and Shima was said to have helped dispose of Endo’s body. These were reported claims about recordings, not independently established facts at that point.

Arai’s disclosures then altered the investigators’ understanding of the missing-person cases. He said he had played no part in the disappearance of the last four victims and identified Shima, his driver, as involved in those disappearances. Arai had learned from Shima that Sekine had killed Endo and Wakui with poison and that Shima had helped bury them. The account therefore separates Arai’s own alleged knowledge from direct participation: his information implicated his former partner while pointing investigators toward Shima as a witness with crucial knowledge.

The police arrested Arai on a fraud charge, judging that an old suspected murder involving his wife would be difficult to prove without a body. Their immediate interest was what he could reveal about Shima; if Shima could be made to talk, Sekine might become vulnerable to prosecution. Thus the partnership’s final consequence was investigative rather than commercial. The former partners’ shared business history gave way to estrangement, suspicion, and testimony that redirected scrutiny from Arai to the relationship between Sekine and Shima.