Michiko Oshitani

Michiko Oshitani’s death is the point where an old friendship, a hidden identity, and a long-running family secret converge: the former classmate who came to see Hiromi Asai’s play recognized Hiromi’s supposedly dead father, Tadao Asai, and challenged him. The investigation later establishes that Tadao killed her, making Oshitani not only a murder victim but the person whose recognition exposed the danger of his concealed life.

Identity and Background

Oshitani was a sales and operations employee whose work brought her into contact with many companies. Colleagues described her as good-natured and caring, cheerful and frank, talkative but without malice. She was also effective in dealing with customers: when a client had a problem, she would set other work aside and visit to resolve it diplomatically. Some customers renewed their contracts because she handled their accounts.

The investigators’ impressions of her were shaped by photographs. Her family’s wedding photograph showed her dressed elegantly and looking demure; a company-trip picture presented a livelier Oshitani, whose cheerful face conveyed warmth. The contrast offered the detectives a fuller sense of the person behind the formal family image.

Oshitani was close to Hiromi Asai at school, and that friendship endured in her interest in Hiromi’s theatrical career. Years later, while visiting Paradise Village, a retirement home, she recognized an elderly woman as the mother of a close junior-high-school friend. She readily agreed to speak with the woman, showing that her connection to Hiromi’s family was not merely a memory from their schooldays.

Friendship with Hiromi Asai

When Oshitani came to the theater to see Hiromi, Hiromi knew she could not simply turn away an old friend. They met in a room at the theater’s office. Oshitani greeted her with unmistakable enthusiasm, praising her appearance and joking about her own middle-aged face. Her lively, voluble manner was unchanged, and Hiromi initially had little opportunity to understand why she had come.

Oshitani’s visit had a personal purpose as well as an affectionate one. She wanted Hiromi to reconsider seeing her mother, whom Oshitani believed was the elderly woman she had encountered at Paradise Village. Though she had originally planned to return to Shiga Prefecture, meeting Hiromi made her decide to stay overnight and see the play. Afterward, she intended to approach Hiromi again about visiting her mother.

Their friendship also became relevant to the police inquiry. A photograph Kyoichiro Kaga found led the task force to consider that Hiromi might be connected to the case. Investigators reasoned that Oshitani and Mutsuo Koshikawa, whose other identity was Shunichi Watabe, might both have known Hiromi. The two women’s shared school history and Oshitani’s continuing attention to Hiromi’s acting career supplied a clear link between them.

Recognition at the Theater

Oshitani bought a same-day ticket for the opening performance at Meijiza Theater. Tadao had gone there because the theater and the production held particular significance for him and his daughter. Oshitani, who knew Hiromi’s father from their earlier life, saw him at the performance. The encounter transformed an ordinary theater visit into a discovery: she had been told that Tadao was dead, yet she saw him alive.

The timing made the sighting suspicious to Oshitani. Hiromi had told her only the day before that her father had died by suicide long ago. Had Oshitani encountered him without that recent disclosure, a father attending his daughter’s performance might not have seemed unusual. Instead, the contradiction prompted her to question him directly. Tadao denied that she had recognized him, but Oshitani did not accept his claim.

After the performance, Tadao encountered Oshitani on her way toward Ningyocho Station. He later told Hiromi that he brought Oshitani to his apartment, offered her tea, and killed her there. His confession established the cause of her disappearance and the immediate reason the case had stalled: the person who had seen through his assumed circumstances could expose him.

Murder and Investigation

Oshitani’s body was discovered on March 30 in a closet in an apartment in Kosuge, Katsushika Ward, rented by Mutsuo Koshikawa. A resident below had complained about foul-smelling liquid coming through the ceiling. When the building manager could not get an answer at the apartment and used a duplicate key to enter, he found the body. The discovery came one week before the family was told of its identification; the postmortem indicated that she had been dead for more than two weeks.

Her relatives identified her belongings, including a watch, handbag, and travel pack. Her sister-in-law was particularly certain about the travel bag, recalling that Oshitani had taken it on a hot-spring trip the previous year. These ordinary possessions established her identity even as the circumstances of her death remained unresolved.

The body was found in Koshikawa’s apartment, but Koshikawa had vanished and residents had not seen him for at least a week. Later, investigators identified a burned corpse found beside the riverbank at Shinkoiwa as Koshikawa and uncovered his previous identity as Shunichi Watabe. They knew Oshitani’s murder and Koshikawa’s death had to be connected but initially could not establish how. The theater encounter and Tadao’s confession supplied the missing connection: Oshitani had recognized him, and her death tied the hidden family history to the two linked cases.

Narrative Significance

Oshitani’s role depends on the combination of loyalty and clear-sightedness. She remains attached to Hiromi’s life after their school friendship, follows her career, comes to the opening night, and hopes to bring her back into contact with her mother. That same familiarity enables her to recognize Tadao and notice the contradiction between what Hiromi had said and what she sees.

The case reconstructs Oshitani’s final movements through other people’s accounts and the detectives’ deductions: the planned return to Shiga, the decision to attend the performance, the sighting of Tadao, and the fatal confrontation. Her absence initially leaves a mystery around the tenant of the Kosuge apartment; the revelation of her choice to question Tadao turns that mystery into a causal link between Hiromi’s concealed family past and the murders under investigation.