The entries posted to a Japanese online discussion board are chilling.
At 5:21 a.m. on Sunday morning, "I'm going to Akihabara to kill people. If my car is destroyed I'll use a knife. Goodbye everyone." and then seconds later, "I'm tired."
At 6:31 a.m., "It's time, I'm leaving."
At 9:48 a.m., "I've entered Kanagawa [prefecture, en-route to Tokyo], I'm taking a rest."
At 11:45 a.m.: "I've reached Akihabara. Today it's a pedestrian area, I think."
Then, finally, at 12:10 p.m., "It's time."
At around 12:30 p.m. a rental truck was driven through pedestrians as they walked across an intersection along the wide Chuo Dori in Akihabara. The road is closed to traffic on Sundays and becomes a "pedestrian heaven" in Japanese. On Sunday it was closer to hell.
Closed circuit TV images, broadcast on Japanese television, show the white truck coming out of the intersection at speed before coming to stop off-camera.
In the moments prior to those images, the truck had hit several pedestrians.
A man can be seen running from the truck towards the busy intersection it's just passed through. The man runs out of view of the camera but seconds later everyone is fleeing in the opposite direction to escape the killer.
Within minutes a suspect, named by local media as Tomohiro Kato, was on the ground, subdued by a police officer. Still images taken at the scene show the detained suspect and a survival knife, apparently blood-stained, lying nearby.
Images from news helicopters that showed paramedics treating people in the middle of the street flashed across Japan. Pools of blood lay on the road. By the evening TV networks were showing cell phone footage shot just after the tragedy.
The death toll rose through the afternoon to hit seven by the end of the day. They ranged in age from 19 to 74-years-old, six were men and one was a woman. An additional 10 people were injured and hospitalized.
The crime stunned Japan. While the grieving begins, questions are already being asked. Inevitably these include "What happened to the social structure of Japan?"
Japan has one of the lowest crime rates in the developed world. The homicide rate was just 1.1 per 100,000 people in 2005, according to figures from Japan's Ministry of Justice. In comparison, the U.K. had a homicide rate of 3.2, Germany 2.9 and the U.S. 5.6, the ministry said.
But more and more these days there are signs that the social fabric that has held Japan together for so long is slowly coming apart at the seams. Where once people had jobs for life and everyone looked out for their neighbors, now many Japanese take temporary jobs to makes ends meet, live in anonymous one-room apartments in vast cities and rarely speak to those around them.
Estimates say up to 1 million out of Japan's population of 128 million simply shut themselves off from the world in their bedrooms. These people, often children, spend their days online, playing computer games and watching television. If they do venture out, it's usually in the middle of the night to a nearby convenience store.
Japan also faces a serious suicide problem. It has the highest suicide rate of any developed nation but the government appears unable or unwilling to do much about it.
In 2006, just over 32,000 people killed themselves -- approximately 87 people per day. While many commit suicide alone, in the last few years group suicides have become more common. The disillusioned often meet up online, make a plan to meet somewhere, and then kill themselves together.
As on Sunday, some choose to take the lives of others rather than their own and these indiscriminate crimes have Japanese thinking their society is less safe than before.
Most people will tell you the 1995 poison gas attack on Tokyo's subway by a religious cult was the start of it all. Twelve people were killed in the attack -- the most deadly Japan has seen since the end of World War II -- and thousands were hospitalized.
Two years later, the nation was shocked by the brutal murder of a school girl in Kobe. She had been killed and her head left on a stake outside the school. But if the murder was to shock, Japan a bigger surprise came when the killer was revealed: a 14-year-old school boy.
The list of gruesome murders has grown longer with time. In 2001, seven years to the day of Sunday's attack, a man entered an elementary school in Osaka in western Japan and killed eight children with a knife. In the same year, a teen hijacked a highway bus in western Japan killing one person.
More recently, a man wanted by police on suspicion of murder stabbed and killed a woman and injured seven others in a shopping mall in Ibaraki, north of Tokyo in March of this year. And in January, a high school student injured two with a knife on a shopping street in Tokyo.