Police have spent nearly quarter of a century hunting a faceless killer they believe murdered a loving family of four in their own home. Mikio Miyazawa, 44, his 41-year-old wife Yasuko, eight-year-old daughter Niina, and six-year-old son Rei, were all found dead on the morning of December 31, 2000, in the Setagaya Ward of Tokyo, Japan.

Detectives discovered the little boy had been strangled to death and his father, mother and sister all died from stab wounds. The  horrifying case shocked the public in Japan, where the chances of being the victim of a murder are around three times less than the UK. 

On the morning of December 30, the family had gone shopping in an arcade near Chitose Karasuyama Station. They later spent the night eating dinner and watching television together. 

According to police, Mr Miyazawa worked for a foreign-affiliated company and was engaged in developing corporate identity (CI) for major corporations. He loved animation, and in school, he was active in puppet and other theatrical play.

His wife Yasuko ran a study class at home. Niina was in the second grade at a public school in Setagaya and enjoyed ballet and piano lessons. Little Rei, meanwhile, was a pupil at a local nursery school. 

The scene of the murder was the family home in Tokyo Municipal Soshigaya Park in 1990 which had shrunk from 200 households in the area to just four by the time of the murder.

To the west of the house is the Senkawa River and there is also a playground, Kishapoppo Park, at the rear of the property. 

But the seeming suburban idyll was shattered when the family were found dead on the morning of December 31. DNA and fingerprint evidence gathered at the scene in the immediate aftermath led detectives to believe the killer chillingly used the computer and ate ice cream inside the home after the sickening attack.

The Japan Times reports a massive police investigation involved more than 280,000 officers over the past 25 years, and police have sifted through more than 160,000 pieces of information but still the murderer remains at large. 

There is still a 20 million yen (£96,700) reward for any information which leads to the arrest of the killer or killers.

As far as any clues that exist for police to go on, the outfit worn by the murderer and abandoned at the scene has proved a long-lasting piece of evidence the police have used in their investigation over the years.

The outfit cops believe the suspect wore included a grey bucket hat, scarf, a Uniqlo ‘Air Tech Jacket’, white trainers, a bum bag, handkerchief and razor sharp sashimi knife, worth around £16. 

Among the clothing items found was a ‘raglan shirt’ of which detectives found only 130 were found to have been sold at the time, just 13 of the purchasers have been identified. 

A mock-up of the killer’s face has never been made as police did not have enough evidence of what he might look like. But what police do know is that DNA analysis found he had blood type A. 

Study of the blood traces is also said to have revealed the murderer had a mother of European descent, possibly from a country from near the Mediterranean or Adriatic Sea. Police said the killer’s father was likely of Asian descent, coming from Korea, China or Japan. He is believed to be about 170cms tall and of thin build.