Between 9:23 and 9:28 AM on May 14, 2026, Eiko Tomiyama (69), an executive of an agricultural corporation, was stabbed over 20 times by intruders at her home in Kaminokawa, Tochigi, and died of hemorrhagic shock. Her eldest son (40s) and second son (30s) were also injured after being beaten with a crowbar. By May 16, the Tochigi Prefectural Police arrested four 16-year-old boys from Kanagawa Prefecture as the executioners. On May 17, they arrested the suspected instructors, Kaito Takemae (28) and his wife Miyu Takemae (25), an unemployed couple from Yokohama. Kaito was apprehended at Haneda Airport just before fleeing the country. Additionally, a 41-year-old man from Ibaraki was arrested on May 7 for possession of stolen goods after being seen in a suspicious vehicle near the victim's home. A total of seven people have been apprehended. The Tomiyama residence was known locally as the 'Burdock Mansion.' Investigations continue into a 'multi-level dark part-time job' structure organized by anonymous criminal groups (Tokuryu). This article organizes all facts known as of May 18, 2026.
Eiko Tomiyama (69) died from 20+ stab wounds; her sons were injured by crowbar strikes.
All four executioners are 16 years old. The instructors are an unemployed Yokohama couple, Kaito (28) and Miyu (25). A total of 7 arrests including a 41-year-old man.
Suspicious vehicles were reported a month prior; the attack occurred in broad daylight despite police patrols.
Kaito was caught at Haneda just before departing.
Complete Timeline: Early April to May 18, 2026
Early April 2026
Reports of suspicious persons and vehicles near Eiko Tomiyama's home begin. Witnesses see individuals on scooters with folded license plates filming the area.
Mid-April 2026
A break-in occurs at the second son's home. One man is arrested in a separate case.
Late April – Early May 2026
The family makes multiple reports to police. Security is tightened.
May 6, 2026
Relatives report a suspicious black vehicle. Police find the car with multiple occupants and stolen plates.
May 7, 2026
A 41-year-old man from Ibaraki is arrested. The vehicle matches one seen at an attempted theft in Shinjuku, Tokyo.
May 14, 2026
9:23-9:28 AM: The incident occurs. Four 16-year-olds in balaclavas enter the home. Eiko is stabbed 20+ times. The sons are beaten when they rush inside from farm work.
May 14, 2026
Instructors Kaito and Miyu Takemae enter Tochigi in a separate car to give orders from a distance.
May 14, 2026
[Executioner 1] A 16-year-old student is caught near the scene after being left behind by the getaway car. He claims he was invited by a classmate.
May 15, 2026
[Executioner 2] A 16-year-old former classmate of the first suspect is arrested in Sagamihara.
[Executioner 3] Another 16-year-old is arrested.
May 16, 2026
[Executioner 4] A 16-year-old from Kawasaki is arrested. He is an acquaintance of the third suspect. He claims he met some members for the first time on the day of the crime.
May 17, 2026
[Instructor 5] Kaito Takemae (28) is arrested at Haneda Airport's international terminal, preventing his escape abroad.
[Instructor 6] Miyu Takemae (25) is arrested.
May 18, 2026
Reports confirm the six suspects had no prior connection to the victim. Police suspect higher-level masterminds.
The Victim: Eiko Tomiyama (69) of the 'Burdock Mansion'
Eiko was a respected female entrepreneur running a major agricultural corporation. Known for building wealth through burdock farming (hence the nickname 'Burdock Mansion'), the family recently shifted to strawberry production. Neighbors described her as a hardworking, humble woman. The fact that the attack happened exactly when the men were in the fields suggests the group had precisely mapped out her schedule.
The Core of the Incident: A 5-Minute Tragedy
The brutality was extreme. Stabbing a 69-year-old woman 20 times, with wounds reaching internal organs, suggests a 'quasi-execution' style rather than mere intimidation for money. The psychological state of the 16-year-olds committing such violence in broad daylight is incomprehensible.
Profile of the Executioners: Four 16-Year-Olds from Kanagawa
All four are the same age and live in Kanagawa. While some were classmates or friends, they didn't all know each other beforehand. This is a hallmark of 'multi-level dark part-time jobs' where recruits are promised higher pay for bringing in friends. These immature teens were transformed into 'killing machines' in just a few days.
The Instructors: The Takemae Couple
Kaito (28) and Miyu (25) are an unemployed couple from Yokohama. Kaito's arrest at Haneda was a dramatic success for the police; a few hours later, he would have been gone. They likely acted as middle-tier instructors for a larger criminal network. A luxury car was seized from near their home, suggesting significant income from these criminal activities.
The 'Multi-Level' Structure
Unlike traditional 'dark jobs' recruited via Telegram, the multi-level model uses a pyramid scheme logic: 'Refer a friend and get a cut of their pay.' This spreads the criminal infection through high school communities like a virus. The 16-year-olds likely got involved through 'a friend's invitation' without realizing they were signing up for murder.
Sentencing and the Juvenile Law
Due to the severity of 'robbery-murder' (which carries the death penalty or life imprisonment), these 16-year-olds will likely be 'sent back' from family court to criminal court to be tried as adults. While they may avoid the death penalty due to age, long-term imprisonment is expected. For the adult instructors, life imprisonment or the death penalty are the primary legal options.
Current Status
Information gathering is ongoing. Updates will be posted on the Miyu Weekly site.
