Killing of Junko Kobayashi

Junko Kobayashi, a 21-year-old fourth-year student at Sophia University, was killed inside her family's house in Shibamata 3-chome, Katsushika-ku, Tokyo, on 9 September 1996. She had been preparing to leave for study abroad in the United States two days later. A fire broke out in the house at around 4:30 pm that day and burned for roughly two hours before being extinguished. Firefighters found her body in the burnt ruins on the second floor and rushed her to a hospital, where she was pronounced dead on arrival due to blood loss from stabbing.

The last recorded conversation with Kobayashi was with her mother, who left the house for work at 15:50 that day, leaving the front door unlocked. A neighbor reported no fire visible at 16:15, but a fire had started by 16:35 and a neighbor called emergency services at 16:39. The fire was fully extinguished by approximately 18:00.

At the crime scene, Kobayashi was found lying on her side on her father's duvet in her parents' second-floor bedroom, with a summer quilt placed over her head. She had been stabbed six times in the right side of her neck and bled to death. Her mouth was covered with adhesive tape, and her arms were also bound with tape; wounds on her hands suggested considerable resistance, and investigators believe her hands were bound after she was killed. Her legs were tied using a specialized "karage knot," a technique used in trades such as landscaping, scaffolding, and kimono dressing. Investigators determined that Kobayashi was already dead before the fire was set, based on the absence of soot particles in her lungs and trachea. A match from a Buddhist altar had been used to ignite a wardrobe on the first floor, and a computer on the first floor was also set alight. Her father's slippers were found left in an unusual arrangement on the second floor, leading investigators to theorize the perpetrator was someone known to the victim.

The investigation, conducted by the Tokyo Metropolitan Police Department under the official case name "The murder-arson case of a Shibamata 3-chome Female College Student," has continued for decades without resolution. In September 2006, a decade after the killing, police disclosed that DNA from a non-family member had been recovered from matchbox residue at the scene. In September 2014, further reporting indicated that a matching DNA profile had also been found in blood on bedding above the victim's body on the second floor. The case remains subject to Japan's special investigation reward system. A jizo memorial named after Kobayashi has been placed at the site of the former house, which no longer stands.