On Feb. 4, 2004, on a cold, snowy day in Gero, Gifu Prefecture, Haruhiko Nokiba's 17-year-old son fell sick. The fevered teen visited a local doctor, tested negative for a flu virus but was prescribed an antiviral drug called Symmetrel. He took a capsule that evening and another the following morning, but he still felt unwell and feverish, so on Feb. 5 he saw a doctor again. This time he tested positive for type A influenza. He was given another, more recently approved antiviral called Tamiflu.

The son, whose name Nokiba would not reveal, came back home, had udon noodles for lunch and, just around noon, took his first capsule of Tamiflu. Nokiba, who is a salesman for a local hotel, had a meeting that afternoon, so at around 2 p.m. he checked his son's room, saw him sound asleep and left home.

Then something bizarre happened. At around 3:45 p.m., police later learned, the teen bolted out the backdoor of the family's detached house, barefoot and in pajamas. He left a line of footsteps in the thick snow as he trotted down a hill, crossed a railway track, climbed over a crash barrier and leaped onto a busy road, where the driver of an oncoming 10-ton truck saw him and slammed on the brakes. But he was not fast enough. The teen was run over and died on the spot.