The three-minute raid that ended a 15-hour nightmare for 364 hostages yielded the arrest of an ailing bank worker, described as an ordinary hard-working man by his neighbours and employers.
"I am sorry for what I have done. I feel regret," Fumio Kutsumi said at the Hakodate central police station. His motives remained unknown. Police needed hours to determine that Mr Kutsumi was acting alone, in Japan's first aircraft hijacking in 16 years. He had earlier triggered a scare by claiming to be a member of the Aum Shinri Kyo doomsday cult .
Police found no indication that Mr Kutsumi was linked with the cult but learnt that he had health problems, including asthma, high blood pressure and nervous disorders, and had been on sick leave from a Tokyo bank since October.
"He just looked like a serious white-collar worker," one of his neighbours said.
Nobuyoshi Takeuchi, president of Toyo Trust and Banking Company, Mr Kutsumi's employer, described him as an "assertive, active employee" who moved fast up the career ladder before his health began to deteriorate in 1991.
The hijacker forced the passengers to put masking tape across their eyes and mouth, and to place their heads between their knees. To make sure passengers complied, the hijacker walked, or ran, around the cabin with his hands buried in a golden vinyl bag that he claimed contained sarin nerve gas. As time passed, he became more aggressive, shouting loudly, kicking people and stabbing one young woman in the shoulder.
It is still unclear how the man managed to bring an 8-in screwdriver on to the plane at Tokyo's Haneda airport. Earlier reports said it was an ice-pick or a boring tool.
Police spent hours trying to investigate the identity of each name on the passengers list.
"We checked them all and eliminated one after another to determine that he was acting alone," said Yasuhiro Chikaishi, security director at the national police agency.
Passengers said that police rushed into the aircraft through three doors and found the hijacker sitting on the floor in the cabin, looking very tired and almost asleep.