On Sunday, Tomohiro, 25, was subdued after stabbing bystanders near the bustling train station of Akihabara, an area known for electronics stores that is a haven for fans of video-games and comic-book culture.
Earlier he had rammed a rented truck into a crowd of afternoon shoppers before getting out and stabbing people.
'Tired of life'
According to Japan's NHK broadcaster, the suspect said he was "tired of life".
|Investigators examining the scene |
of Sunday's crime [Reuters]
Stabbing attacks in Japan, once rare, have become more frequent in recent years, along with an increase in violent crime.
In March, a man with two knives stabbed one person to death and injured at least seven others outside a shopping centre in eastern Japan.
In one of the worst attacks in the country, a man with a history of mental illness burst into an elementary school in 2001, killing eight children with a kitchen knife.
The killer was executed in 2004.