A 65-year-old female owner of a bar in Sugito, Saitama Prefecture, was found dead with a kitchen knife stuck in her chest, police said.
Kazuko Makiuchi was found lying in the bar a little after 6 p.m. Friday by her eldest son, Kazuo, a 35-year-old company, the police said.
The son, who lived with his mother in Sugito, went to the bar Friday after his mother did not return home Thursday night.
The bar's main door was unlocked, the police said, and there were marks on the floor from chairs and tables being moved. The Saitama Prefectural Police opened a murder investigation.
The woman managed the bar by herself.