[Video Released] Murder, a Body Hidden Under the Floor, and 10 Years of Living Hell Inside a Tormented Family

She killed her mother-in-law after being unable to bear her demands for money

“The defendant had no way of escaping the victim other than committing this crime.”

As the defense attorney began the opening statement before the witness stand, the woman covered her face with both hands and began to cry──.

The trial was held at the Saitama District Court in 2025. The defendant was Harumi Tanaka (pseudonym, 55 at the time), who, unable to endure years of mistreatment by her mother-in-law (68 at the time), impulsively killed her one day.

The crime came to light in 2023 after the victim’s eldest daughter, who lived with her, called 110 and reported, “My mother is dead.” The person arrested the following day on suspicion of abandoning a corpse was Harumi Tanaka, the wife of the victim’s eldest son. She subsequently told investigators, “I strangled my mother-in-law and killed her,” and was rearrested on suspicion of murder.

During questioning, Tanaka reportedly said, “She questioned me every day, accusing me of secretly having money hidden away, and I was furious.” The incident initially appeared to have been caused simply by an increasingly bitter relationship between a wife and her mother-in-law. But in court, the anguish of the defendant, who had been driven to the brink every day by baseless accusations from the victim and suddenly reached her limit one day, came to light, along with the distorted family relationships that lay behind it.

The circumstances of the incident revealed at the first hearing were as follows.

After getting married, Tanaka lived with her husband and son in Niigata City, but around 2014, the family moved to a maisonette-style apartment in Saitama City. At the apartment in Saitama, her husband’s mother and two younger sisters joined them, bringing the household to six people. Tanaka was reportedly at the bottom of the family hierarchy.

“The defendant’s mother-in-law, who became the victim, openly declared that ‘I am the central figure in the Tanaka family.’ She ordered the defendant, who held the lowest position, to get up by 5 a.m., gave detailed instructions on everything from the colors of the ingredients to put in the family’s lunch boxes to the number of dishes served at dinner, and required her to report what time family members entered and left the house and whether they had eaten.” (From the defense attorney’s opening statement)

“I heard a snap inside my heart.”

At one point, Tanaka’s mother-in-law reportedly came up with a plan to get money from Tanaka’s parents.

“She had Tanaka make a phone call according to a script she had devised, ordering her to go get money from your parents. Between August 2018 and June 2021, Tanaka had her parents send her more than ¥7.7 million, which she then handed over to her mother-in-law. The guilt of lying to her own mother to deceive her out of money, combined with the dilemma of being unable to disobey her mother-in-law’s orders, took a toll on her mental health, eventually leaving her in such a poor state that she required treatment at a psychosomatic medicine clinic.” (Same source)

The trigger for the incident was the mother-in-law’s claim, in 2023, more than five years after Tanaka had supposedly handed over ¥1.5 million in 2018, that she had “never received it.” Her mother-in-law persistently demanded that Tanaka “give me the remaining ¥1.5 million,” and even when Tanaka insisted, “I’m sure we checked by searching through my belongings,” the mother-in-law refused to believe her. The same exchanges reportedly continued day after day.

Driven to the limit, Tanaka was arguing with her mother-in-law on the morning of the incident when she suddenly felt as though a fog had descended over her eyes and her mother-in-law’s voice sounded distant. According to Tanaka, after she heard “a snap inside my heart,” she impulsively strangled her mother-in-law to death with a plastic cord. She then hid the body inside an underfloor storage compartment so that it would not be discovered.

Because Tanaka admitted to the crime, the focus of the trial became the motive behind her actions.

What she described in court were the hellish days she had endured at the bottom of a family hierarchy headed by her mother-in-law—being treated as someone lower in status than even a cat. She had been ordered by her mother-in-law to lie to her own mother and repeatedly beg her for money. She also spoke of her inner conflict over having caused her family trouble and then being separated from her mother by death without ever making amends.

At the sentencing hearing, the presiding judge acknowledged that “it is understandable how the defendant felt” after being subjected to repeated and unjustified demands for money, and showed a degree of understanding by stating that she had been routinely mistreated within the family and that “it is a fact that she was placed in an unreasonable situation.”However, the judge also ruled that “it is difficult to say that she was in a situation where she had no choice but to resort to murder, and she cannot escape an appropriate degree of condemnation,” and sentenced Tanaka to seven years in prison. The defense had argued that “she had no way of escaping her mother-in-law’s abuse other than killing her” and sought a suspended sentence, but that argument was rejected.

Until then, Tanaka had sometimes become emotional during the trial and even shed tears, but she reportedly listened to the verdict without changing her expression. What was going through her mind at that moment──?

A YouTube video provides a detailed explanation of the distorted family relationship between Tanaka and her mother-in-law revealed during the trial, as well as the mother-in-law’s behavior in continually extracting ¥7.7 million from the defendant.