A suspended prison term handed down six years ago was not enough to stop the 34-year-old gas station worker from using amphetamines, which had already badly damaged his life.

On the day he was released from the detention house, he rushed to a drug dealer.

"I was like a complete slave, doing anything to get the 20,000 yen to buy stimulants that I needed every day to get by," said the man, who asked that his name be withheld.