The attacker reportedly used a samurai sword to attack his sister, the head priestess of the shrine.
The attack, which took place at the Tomioka Hachimangu Shinto shrine, a religious establishment outside of the city, was captured on tape by nearby security cameras.
The attacker was Shigenaga Tomioka, brother of chief priestess and murder victim Nagako Tomioka. Tokyo Metropolitan Police say that Shigenaga’s girlfriend was also involved in the attack, as well as Nagako’s chauffeur.
Police suspect that Shigenaga confronted his sister outside of the shrine on Thursday night, and stabbed her in the chest and stomach with a blade. The girlfriend, yet unnamed, chased down the chauffeur with a traditional Japanese samurai sword, slashing his arm and chest. He was able to escape his attacker.
“The two attackers then moved to the shrine premises, where Shigenaga Tomioka stabbed his accomplice in the chest and stomach and then stabbed himself in the left side of the chest multiple times,” the Japan Times reported.
Police believe that the murders were sparked by a longtime feud between Nagako and Shigenaga.
The sibling’s father had been the chief priest before Nagako, and had originally appointed Shigenaga as his successor. However, in 2001 Shigenaga was let go for unknown reasons, and their father appointed Nagako in his place.
According to police reports, Shigenaga began sending Nagako threatening letters after his removal, which culminated in his arrest in 2006.
“Shigenaga Tomioka was arrested some 10 years ago for blackmailing his sister,” the Japan Times reported. “After he left the post of chief priest in 2001, he sent a threatening postcard to his sister in January 2006 in which he wrote, among other things, that he would send her to hell.”