The number of Japanese who killed themselves in suicide pacts made over the internet rose sharply last year.
Suicide pact deaths have shocked Japan
Police said 91 people died in the pacts in 2005, compared with 55 in 2004 and 34 in 2003, when the records started.
Alarm at the rise has led to increased vigilance by internet service providers, who now report suspected suicide pacts to the authorities.
Japan has one of the highest suicide rates in the world, and the pacts may appeal to those scared to die alone.
Police figures showed 34 internet-arranged suicide pacts were recorded last year. Of the 91 people who died, 54 were men and 37 were women, with most being in their twenties or thirties.
But the number of cases may now be falling. Twenty of the 34 cases took place in the first three months of last year, before internet service providers started working with the authorities to tackle the problem.
In one case in February, three men and three women who had contacted each other via the internet shut themselves in a car and lit charcoal burners, poisoning themselves with the carbon monoxide.
Suicide has become a widely discussed topic on many websites in Japan, and there is even a guidebook to the best places to kill yourself.
The authorities have talked about closing down or regulating the websites.
But organisers argue that they offer a compassionate service to those who have given up all hope of the future.
Increasing numbers of young people in Japan are feeling alienated by modern life. Several thousand are termed "hikikomori" - recluses who never leave their room, finding entertainment only on the internet.
The suicide pacts still make up a relatively small proportion of Japan's suicides.
More than 34,000 Japanese took their own lives in 2003, according to the National Police Agency - an increase of more than 7% from the previous year.