Transcript: 79. Miyazawa Family Murder Mystery | Japan

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The light from the computer shone on the man’s face as he looked at the screen. He licked an ice cream directly from its paper cup and clicked through all the bookmarks on the web browser, looking at one website after the other.

Outside the study door, the house was dark and quiet. Too quiet.

A young family of four lay dead, killed by the man who was in no hurry to leave. He made no effort to conceal his identity, leaving his fingerprints and DNA throughout the house. This killer was callous and confident, like he knew he would never be caught… 

>>Intro Music

The Miyazawa family planned to celebrate New Year’s Eve of 2000 going into 2001 – at home, having a quiet night, sharing a special meal together, looking forward to the year ahead. 

The happy family of four was a quiet, normal suburban family who lived in Setagaya, a ward of Tokyo. Father, Mikio was a 44-year-old businessman who worked in corporate identity development for Interbrand, a London-based, international media and marketing company with branches in 19 cities around the world. Mikio worked from home and the study on the ground floor was his home office.

41-year-old mother, Yasuko, was a teacher who was well liked by her students, their parents and her co-workers. They had two children: Niina eight years old and a son, Rei who was six. Rei had a speech impediment for which he received specialised treatment.

Setagaya is a beautiful, quiet suburb with space – a rarity in the densely populated city of Tokyo. The Miyazawa family lived in a duplex, which is a large home that had been split in half. Yasuko’s mother, Ashai Geino, lived in the other half of the house. The property was adjacent to Soshigaya Park with walking trails, sports pitches, a playground for kids, and a quaint tree-lined canal.

The Miyazawa family moved into their home in 1990 and loved the lifestyle it offered. But a couple of years later, council had planned on developing the area into a recreational park and bought all the homes in the direct area to make way for expansion. 


By December 2000, the Miyazawa family was one of only three families who remained in the neighbourhood. Where 200 homes were once inhabited it had become a desolate neigbourhood. The Miyazawa family had plans to move out in 2001 sometime.

Although there weren’t many residents in the direct area, the skatepark next to their home in Soshigaya Park became busier and busier. Mikio even had to tell off some noisy teenagers outside their home for disturbing them. He also confronted members from a biker gang, Bōsōzoku, because they were being loud. The influx of people clearly stressed him out quite a bit.

Yasuko’s older sister worked and lived in the UK and at the time, she was in Japan with her husband, looking forward to celebrating the New Year with her family. During the visit, they stayed next door to Yasuko and her family, with their mother.

On the morning of the 31st of December, Yasuko’s mother, Asahi tried to call the Miyazawa home, but the call would not go through. Although they lived next door to each other, they respected each other’s space and never dropped by unannounced. Asahi tried calling a couple of times, but she still could not reach them. Their car was in the drive and it was very unusual for them to screen calls. She decided to go around to check on them, but nobody answered the door. When she tried to go in, it was locked. She went back to her place, got the key and went back to let herself in.

What she found, was a grisly scene… The whole family had been killed in an act of unimaginable violence. 

First she found her son-in-law, Mikio’s body on the floor. He had multiple stab wounds to the neck and from the position of his body, it looked like he had fallen down the stairs.

The grandmother was horrified and rushed upstairs to see where her daughter and grandchildren were. She found Yasuko and Niina slain, lying in a large pool of blood at the top of the stairs. Both were stabbed multiple times. Yasuko’s mother hoped to find her grandson alive, and ran to his room. But he too, was deceased, in his bed, strangled.

She called police, hysterical, asking them to come as quickly as they could. 

When police arrived at the scene, the found the house in disarray. Many documents were strewn around and it looked like somebody had slept on the sofa in the living room. Behind Mikio’s body was a chest of drawers, with each drawer pulled out and papers protruding from them. One of the drawers was missing and investigators found it in the bathroom with all its contents in the bathtub. In the bathtub they also discovered bloodied bandages and garbage – a strange collection of things to be thrown in a tub. 

Police found a large amount of cash in Mikio’s study – 150,000 yen as well as foreign currency to the value of 5,000 yen. The only missing item was an old jacket of Mikio’s. Because the killer left his bloodied clothes it is possible that he left the scene wearing Mikio’s jacket. Other than that – nothing else was missing, which meant that robbery could not have been the motive for the murders. 

Walking through the three-level house, police found a screen that had been cut and removed from a window in the bathroom on the second floor. The bathroom was located towards the back of the house and could be reached from the fence between the property and the park. This looked like the most likely point of entry, as all the other doors and windows were closed and locked. From the outside, they could see footprints on the wall below the window. 

Walking from the bathroom, the children’s bedroom was the first room to the right. Police believed that the killer went into the bedroom where little Rei was asleep in the bunk bed he shared with his sister and strangled him with his bare hands.

Mikio most likely heard some movement upstairs and went to check on his son. When he reached the top of the stairs, he was stabbed with a sashimi knife and then pushed down the stairs.

Little Niina was next. The killer found her in bed next to her mother in the third floor loft, that could only be accessed using a drop-ladder. Halfway through the attack, he realised  that the tip of the sashimi knife had broken off during his attack on Mikio, so the killer left.

At this point, Yasuko and Niina probably thought the assailant had gone, so they made their way down the ladder to the landing where Mikio was attacked. Yasuko fetched the first aid kit and tried her best to save her daughter. But the killer was not done, he came back with one of their own kitchen knives and found them at the top of the stairs, where killed them both. 

The attack on mother and daughter was the most violent of the four murders. He continued stabbing both of his female multiple times after they had perished. From wounds on Yaskuko’s body it was evident that she tried her best to fend the attacker off, desperately shielding her daughter from him. But he was not deterred and made sure he finished the job.

During the attack the killer cut his hand and used bandages from the family’s first aid kit to tend to his wound. He also used sanitary pads he found in the bathroom to stop the bleeding. 

Then he simply stayed in the home that was a happy family home only hours before. He ate melon and ice cream from their fridge, made himself some barley tea. He used their bathroom, unplugged the phone cord and slept on their sofa. 

At 1:18am, he logged on to the family computer and tried to buy theatre tickets using Mikio’s credit card. But he did not complete the transaction, as he did not know all the relevant security information. He opened browser bookmarks to the website for the company who employed Mikio, as well as the website of the school where Yasuko worked. 

It wasn’t clear if he was online all night or if he logged in again the next moring, either way, there was some activity on the computer at 10am on the morning of the 31st. 

Asahi entered the home at 10:55 and police felt they could not exclude the possibility that she could have brushed against the computer to inadvertently show up as computer usage. If it wasn’t her, chances are that the killer left only minutes before she entered. When he left, he left both murder weapons – the sashimi knife and the kitchen knife – on the kitchen table.

There was an abundance of forensic evidence at the scene. The killer left the first aid kit covered in both Niina’s blood as well as his own blood. He also left faeces floating in the toilet and never flushed. His hip bag (that is a small back pack or larger kind of fanny pack) contained traces of sand that could be traced to the United States. They were able to trace it all the way to a specific location: the area around Edwards Air Force Base in Nevada. There was also a roll of tape, often used by skateboarders to fix their boards. Something that seemed a bit out of place inside the hip bag was a folded and ironed hankerchief with traces of French cologne, Drakkar Noir by Guy Laroche - a brand popular with skaters at the time. 

Many footprints were found around the house, which provided interesting clues. The perpetrator wore a Slazenger shoe – but the exact size of the shoe he was wearing, was never sold in Japan. In fact, that size was only ever sold in South Korea.

He also left his blood stained clothes behind. But in contrast to the way he left the drawers, documents and discarded the ice cream cups, his clothes were left neatly folded at the scene. There were gloves, but he didn’t use them, as his fingerprints could be found all over the house. In fact, forensic technicians were able to lift a complete set of fingerprints from evidence found throughout the house. 

The clothes had been washed in hard water, with a higher mineral content, not like the soft water in Japan. The type of water used was common in Korea, however. Police traced the purchase of the sweater and the knife to the Kanagawa Prefecture. Only 130 of the same sweaters were ever sold, but police were only able to track down 12 of the owners. So if the sweater was purchased in Japan but washed in Korea, perhaps the killer lived in Japan and travelled to Korea in the time leading up to the murders? Perhaps the sweater was manufactured in Korea and had not been washed in Japan since he purchased it?

A genetic profile compiled from blood found at the crime scene showed that the unknown person was of mixed race. The killer’s mother was of Southern European descent, the father East Asian. DNA showed a special sequence of genes that is can only be found in someone from Chinese, Korean or Japanese descent. The type of profile could be found in 1 of 5 men from Korean descent, 1 in 10 Chinese men and 1 in 13 Japanese.

Investigators favoured the idea that the killer was a foreigner. It was easier to accept that such a monster was not one of your own. Japan’s Special Search Division sent investigators to Korea to liaise with local law enforcement, but they could not help in identifying the murderer.  

Throughout the years, the theory that the killer was Korean has been placed in the forefront. The fact that the killer could have been Japanese – there was a one in 13 chance  after all, did not really work into the investigation. He could also have been a first or second generation Korean-Japanese person. 

Investigators set out to find a mixed race person in various parts of Japan: the Korean expat community, the diplomatic community – perhaps the maternal European connection could have provided a clue… But no one matching the killer’s DNA or fingerprints could be found. Because of the origin of the sand in the hip bag, police wondered if the killer was perhaps a military person. US forces have been present in Japan since the end of World War II – could he have been a second generation Korean/Japanese or Chinese American citizen? 

Despite the mountain of evidence, police simply could not figure out who the killer was. They went back to the drawing board and look at the Miyazawa family’s relatives and connections to try and find anyone who could have had a motive to murder them. But friends and family of the victims had no idea who would want to kill them. They had no known enemies and were well-liked within the community. Mikio told off skaters for being too loud at the skatepark next to their home, but that was as aggressive as things got. Surely that would not have been a reason to brutally murder a man and his family.

Forensic evidence from the faeces left in the toilet showed that the intruder had eaten sesame seeds and string beans – a very common dish in Japan, mostly associated with home cooking. This was not consumed at the Miyazawa home and the killer must have had it before he committed the murders. Police considered the idea that the man still lived at home with his mother.

Investigators drew up timeline of events leading up to the horrendous night. In the six months before the murders, there were many reports of animals being killed and mutilated in the park next to the Miyazawa home. Local residents found a skinned cat in August 2000.

Later on in the investigation, police were able to find the person responsible for mutilating the animals. He was a bank clerk and his actions were not connected with the Miyazawa family murders.

On the 25th of December, Yasuko told her father-in-law that a strange car parked in front of their house from time to time. There was no reason for a car to be there, as entry to the park was on the other side of a fence.

Two days later, they noticed a strange man walking around the home. On the 29th of December, residents of the area recalled seeing a strange man walking around the shops at Seijogakuenmae train station. He was in his late 30’s or early 40’s, wearing skater gear – in fact, the same type of clothing found at the crime scene. People found this odd, especially for the time of year – he did not seem to be dressed warm enough. One store owner told police that the man bought a sashimi knife – it was the only knife sold on that day. Forensic testing proved that it was in fact the knife used by the killer.

The next day, a neighbour of the Miyazawa family, saw the same man from before walking around their home again. Nobody was home, as they had all gone out shopping. 

The witness gave a clear description of the stranger and told police that he wore a grey wool hat with a black stripe. He had a hip bag, a colourful scarf, a black Uniqlo jacket, gloves, a long-sleeved T-shirt, and white Slazenger shoes. Most of these items were found inside the Miyazawa home after the murders. 

At 7pm on the night of the 30th of December, Yasuko called her mother on the phone, to tell her that they had just arrived home. The grandmother wanted to know if the kids wanted to come over to watch television. Rei wanted to stay at home, but Niina wanted to go. She went next door for a couple of hours and left sometime between 9 and 9:30pm to go to bed.

The last recorded action in the Miyazawa home was on the family computer. Mikio opened a password protected work email at 10:38pm. It is unlikely that anyone other than Mikio would have known the password to read the email.

At 11pm, a neighbour was out for a walk in the park when he heard an altercation inside the home. It did not sound like a physical fight, rather like a husband and wife having an argument. Around 11:30 Asahi and Yasuko’s sister heard a loud thud next door. They were still awake, watching television. Around the same time, a witness saw a man briskly walking away from the house. 

Asahi told police that the light on ground floor and the entrance hall way was on when she arrived after 10am the following morning. But a paperboy who delivered paper on the 31st said the light was NOT on that morning.

After the murder a taxi driver came forward and told police that he had picked up three middle-aged men in near the Miyazawa family home. It was eerily quiet in the car, almost too quiet. When they got out, there was a bloodstain on the back seat. The taxi driver recalled that one of the men was wounded. 

On December 31st, a young man went into a medical centre at Tobnikko Station – approximately 70 miles north of the Miyazawa family home. Medical staff treated a wound on his hand – a cut so deep the bone was exposed. Staff recalled that the man was very calm and did not seem too concerned about his wound. They found his behaviour strange, because the wound was rather serious. They told police that the man was dressed in a black down jacket and jeans and he was in his 30s. He did not provide a name or an address and left the centre without providing any information. 

This sighting was only deemed to be significant later-on in the investigation. Police initially thought that the killer left the scene in the middle of the night, but as the scene was processed and results from blood tests came back, they concluded that he left mid-morning, moments before Asahi entered. By the time the information from Tobnikko station’s medical centre was examined, several months had passed and police had no way of finding the man.

In 2018, Tokyo police released information about their suspect to the public, hoping someone would be able to help bring him to justice. The information, based on all the evidence found at the scene, concluded that the perpetrator was a young man between the ages of 15 and 20 years old. He is 170cm tall and by studying the knife wounds on the victims, they could tell that he is right-handed. He could have been a drifter or an illegal immigrant, which explained why he could not be traced. 

The fact that the perpetrator was concluded to have been younger than the initial estimation of 30-40 years old, made police consider that he could have been the son of a diplomat, the son of a soldier or the son of a wealthy local family who was perhaps of of the skaters who clashed with Mikio in the months leading up to the murders.

Japanese true crime author Fumiya Ichihashi released a book in 2015 called The Setagaya Family Murder Case: 15 years on, the new facts. In the book, he claims that he had pieced together the clues and solved the mystery as to the killer’s identity. Ichihashi said that soil from the killer’s shoe found at the crime scene was traced back to the province of Gyeonggi in South Korea. He investigates a suspect who he refers to as ‘R’  - an man who had served time in the Korean army. 

According to Ichihashi, the motive for the murder was money. Each family living along the border of the park was paid 100 million yen by local council to evacuate their homes. However, if money was the motive, why did the killer leave all the cash at the scene? 

In the months after the murders, a quarter million cops worked on the case. Murderous home invasions in Japan is not common at all and authorities were adamant to catch the killer. However, despite all the evidence in the case, police were never able to the murderer. 

Today, 40 officers are still working the case, re-reading casefiles, re-interviewing witnesses… They often visit train stations near the Miyazawa’s home, handing out flyers with information about the killer’s clothing and appearance, hoping someone will come forward with new information. A 20 million yen reward has been offered by Tokyo Metropolitan Police Department for anyone who could help police solve this 20-year-old mystery.

Every year, officers congregate at the Miyazawa home to pay respects to the family and promise that they will never give up in the quest of bringing their killer to justice. The house is empty, boarded up and has become a mausoleum of the Miyazawa family. In recent years local council wanted to demolish the building, but the family will not allow it.

This case has been referred to as “The Japanese Hinterkaifeck” because of its similarities to the famous unsolved German case from 1922. In both cases an entire family was murdered, the killer remained in the house with the corpses for hours and both cases are unsolved. 

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