Police found the remains at a house owned by 72-year-old Yasuo Iihoshi after a family member had reported that his calls had gone unanswered, according to Miyazaki prefectural police.
One of the bodies, a female, was discovered outside the property, while three males and two more females were found inside the house.
Japan, which ranks as one of the safest countries in the world to live, has a very low murder rate and mass killings are rare. Given Japan’s strict gun laws, in the infrequent attacks that do occur, knives are more commonly used.
In the Takachiho killings, at least some of the victims had been stabbed, local media reported. The murder weapon has not been recovered.
Authorities have released the names of the victims, including Yasuo Iihoshi, his 66-year-old wife Mihoko, their 7-year-old granddaughter Yui, 41-year-old daughter-in-law Mikiko, and 21-year-old grandson Takumi.
They are all members of the immediate family of Iihoshi’s second son, Masahiro.
The sixth victim was named as 44-year-old Fumiaki Matsuoka,who is unrelated to the family but a friend of Masahiro’s.
Masahiro Iihoshi has been missing since the discovery of the bodies. The police also discovered a seventh body under a bridge crossing the Gokase River.
Famous tourist destination
The Kyushu town is famous for the nearby, scenic Takachiho Gorge, and the area is an important site for Shinto myth and legend.
Japan’s deadliest mass killing since World War II was recorded in 2016, when at least 19 people were killed and 26 injured in a stabbing spree at a facility for disabled people west of Tokyo.
Satoshi Uematsu, the suspect in the case, had written a letter several months before the incident, in which he said he had “the ability to kill 470 disabled people.”
The death count from that attack eclipsed the infamous Aum Shinrikyo subway sarin gas attack of 1995, that killed 13 people and injured more than 6,000 others, which itself was part of a murder spree throughout the country that left 29 people dead.