Hours That Made No Sense
What happened next is, in many ways, the most unsettling part of the case. Rather than flee, the killer stayed in the house for several more hours.
Between roughly 1:18 and 1:23 a.m., he sat down at the family’s computer, created a new folder, browsed a bookmarked theater website, and attempted — unsuccessfully — to use Mikio’s bank card to purchase tickets online. He then wandered into the kitchen, eating ice cream directly from the containers, slices of melon, and drinking nearly four bottles of barley tea from the fridge, all without bothering to use utensils.
Afterward, he went to the bathroom, dumped food waste in the bathtub, and used the toilet without flushing. He treated his own wounds there with items from the family’s first-aid kit and sanitary products, unknowingly leaving blood evidence throughout. He rifled through drawers, papers, and personal belongings, scattered the house keys between the bathtub and toilet, and eventually took around 100,000 yen (roughly $625) in cash — while leaving jewelry and other valuables untouched.
At some point, he rested on the living room sofa, where he neatly arranged his own belongings: a sweatshirt, jacket, gloves, hat, scarf, hip bag, and two handkerchiefs. Sometime after 1:30 a.m. — and before mid-morning — he left the house through the same window, without taking any of what he’d left behind.
A Grim Discovery on New Year’s Eve
The bathroom window remained open. The front door stayed locked from the inside. And the house sat silent until around 10:40 a.m. on December 31, when Haruko, unable to reach the family by phone, let herself in and found them.
She discovered Mikio first, at the foot of the stairs near the front door. Rei’s body was still on the bunk bed. Yasuko and Niina were found together near the attic ladder, their bodies positioned back-to-back — a detail investigators have long read as a mother’s last attempt to shield her daughter.
Police arrived to a scene officers later described as jarring in its contradictions: extreme violence alongside oddly domestic details — half-eaten food, an unflushed toilet, a computer still switched on, and personal items folded with almost obsessive care on the sofa. One investigator would later describe the killings as carried out with an almost casual cruelty, “as if for fun” — language that stuck with the case for years afterward.
Piecing Together the Night
The reconstruction of events was, in forensic terms, unusually clear. There was no forced entry anywhere in the house; the discarded window screen and matching muddy shoe prints confirmed the point of entry, and prints in the soil beneath the window lined up with those found inside. Investigators were able to trace the intruder’s exact path — first to Rei’s bed, then into the stairwell confrontation with Mikio, and finally up to the attic.
Estimated time of death for all four victims fell between roughly 11:30 p.m. and 12:05 a.m. Beyond that window, though, almost everything else about the case became a matter of debate that would stretch across the next quarter-century.