These revelations by Tomohiro Kato, 25, who killed seven people and injured 10 others in a stabbing rampage, were found in messages he posted on a cellphone website four days before the attack.

'I had been forced to play the good boy since I was little,' he wrote in a series of bitter postings.

Kato's classmates remember him as a student who excelled in both studies and sports from primary to junior high school.

But he wrote: 'My parents forced me to study so my studies were perfect. They wanted to boast about their son, so they made me perfect.

'Even my essays were censored by my parents.

'I won prizes with essays written by my parents. I won prizes with drawings drawn by my parents.'

Kato started to rebel against his parents after joining an elite senior high school, neglecting his studies and instead developing a passion for cars, video games, animation and military- style mock war games. His last job was at an auto parts factory.

Japanese tabloids have reported that he and his younger brother had even beaten up their mother before.

Last Sunday, Kato drove a two-tonne truck into a group of pedestrians at Tokyo's Akihabara district, before jumping out and stabbing random passers-by. He was subsequently overpowered by the police.

During interrogation, Kato reportedly told police, with tears in his eyes, that his parents were 'very strict' and he did not get along with them.

Kato's father works for a financial institution in Aomori city, northern Japan, where he was born, while his mother is a housewife.

On Tuesday night, his parents, their heads bowed deeply throughout, told reporters outside their home that there was no way they could atone for what their son had done.

'We are terribly sorry for the people who lost their lives and were injured by what our son did,' his father said.

'No matter how many times we apologise, we cannot ever make amends.'

Kato's mother, who celebrated her 53rd birthday just a day before the killings, broke down in tears and collapsed during the brief interview.

Their first names have been withheld by the media for privacy reasons.

Kato, who told investigators he was mentally ill, is expected to be sent for a psychiatric evaluation to determine whether he is competent to face trial. He could face the death penalty if he is convicted.

In some 3,000 messages posted from his cellphone, Kato had aired his anxieties about being fired from his job, his inability to make friends or get a girlfriend, and even the way he looked.

Criminal psychologist Akira Sakuta said that by repeatedly thinking negative thoughts, Kato had probably developed a hatred for himself, out of which emerged a desire to destroy and kill others.

Mr Naoki Ogi, a well-known commentator on educational issues, said the incident reflected deep social problems in Japan, where as many as 10million young people are said to face bleak futures with jobs that pay wages too low for them to get married or start a family.

Kato had written in one post that, since leaving school at the age of 18, 'my life has been that of a loser'.

'We need to give hope to such young people. They feel they are in a 'sliding society' where the only way is down,' Mr Ogi said.

Meanwhile, Japanese video game maker Konami has cancelled a launch event it was planning to hold today in Akihabara and two other locations in Tokyo for Metal Gear Solid4, a popular action game featuring graphic violence.

Yesterday, the Japanese government called a meeting of eight Cabinet ministers to discuss whether controls on knives needed to be tightened.

wengkin@sph.com.sg