A man and a woman were found slain Monday, in Nagoya and in Chiba Prefecture.
The man was found lying on a street in Nagoya's Meito Ward with about a dozen stab wounds. He was declared dead at a hospital early Monday, police said.
Authorities investigating the slaying of Masatoshi Komura, 33, said little blood was found at the scene even though the victim had been stabbed in the neck and back several times. Komura's neck also bore marks of strangulation and his face was badly bruised, they said.
An autopsy is scheduled.
A passerby called police at around 2:50 a.m. Monday after finding Komura on the ground about 1 km southeast of Hongo subway station. Komura's address and occupation were not immediately known. He was wearing a shirt and jeans but other belongings were not found at the scene, police said.
Meanwhile, a woman was found dead Monday with a chest wound in her ex-boyfriend's apartment in Urayasu, Chiba Prefecture, police said.
The woman, believed in her 20s and from Miyagi Prefecture, was found on a bed covered with a blanket, police said, adding no murder weapon was found and that the case is being treated as a homicide.
The police said the ex-boyfriend, a 23-year-old employee, called at about 8:05 a.m. Monday to report that a female acquaintance was dead in his apartment.
The man said she was visiting him for Golden Week and apparently used a spare key in the mail box to let herself in around 3 p.m. Sunday while he was out. He found her dead when he returned from work Monday morning.