TOKYO, JULY 14 -- Ryoko Ishida, 15, reached school a few seconds late last week and lost her life as a result.

On the morning Ishida chose to be tardy for the first time in her high school career, three teachers were waiting in the schoolyard, determined to discourage latecomers. As the bells chimed at 8:30 a.m., one teacher sent the school's 500-pound iron gate hurtling closed on its tracks. At that moment, the freshman girl had reached the gate and was crushed against a concrete wall. She died two hours later.

Police are now investigating Ishida's death, which has rekindled debate here about the rigid, intrusive and sometimes humiliating discipline and rules of many Japanese schools. "This is a story that freezes our heart," said the Asahi newspaper.

The principal of Ishida's high school in Kobe city, Atsuo Nomura, called an assembly to express regret at Ishida's death. But while addressing the 1,500 boys and girls, who were sitting on the floor in neat rows and clad in uniforms of white shirts and dark trousers or skirts, Nomura also suggested that the students were to blame.

"If more of you would come 10 minutes earlier, teachers wouldn't have to shout, 'Don't be late!' " Nomura said. "I have no intention of denying my responsibility, but I would like all of you to think again about your basic lifestyle."

An angry response came from Hiroshi Kume, one of Japan's most popular television newscasters, who has focused on the case nightly during his 10 p.m. news show since Ishida died last Friday. "I think he doesn't really understand what it means that a 15-year-old girl lost her life," Kume said, referring to the principal. "This is really a murder case."

In fact, police said they are investigating teacher Toshihiko Hosoi, 39, on a lesser charge of professional negligence resulting in death. A police spokesman in Kobe said Hosoi told them he was looking downward when he pushed the gate closed and could not see anyone coming.

But many commentators said Ishida's death is not just a local crime, but also a reflection of an obsession with school rules on the part of many educators.

"The root of this incident is not in this school, but in junior and senior high schools all across Japan," said Takeshi Hayashi, who has written a book protesting school rules.

Japanese education is often praised abroad for turning out universally literate graduates who score near the top of world scales in math, science and most other subjects.

But it is sometimes criticized for discouraging creativity and independent thought and for regulating the most minute details of students' dress and behavior.

Besides requiring uniforms, many schools regulate the color of underwear, demand that girls' white socks be folded in a certain way and mandate shaved heads for boys. Others tell students they may not date, go to movies, leave home after sunset or play video games without permission from the school.

Infractions are often met with beatings or other corporal punishment or, less often, with measures aimed at public humiliation, such as being forced to expose one's underwear or lick a teacher's foot.

This week, the Fukuoka school board announced that it is investigating seven junior high school teachers for burying two students in sand up to their necks and leaving them, at ocean's edge, for 20 minutes. The two eighth-graders had angered the teachers by refusing to admit that they had extorted money from classmates, as the teachers suspected.

The lead columnist of the Asahi, Japan's most liberal mass-circulation newspaper, expressed "amazement," "anger" and "puzzlement" at the teachers' behavior. "What they did was nothing more than a case of collective violence," Asahi said.

But the local school parents' association, meeting Friday, voted to support the teachers' actions, in what many experts here say is a typical response from parents fearful of juvenile delinquency and anxious for their children to fit into this highly ordered, group-oriented society.

"We should not tone down the spirit of our teachers," the chairman of the parents' group said, according to the Japanese press. "We need this discipline."

At Kobe Takatsuka High School, where Ishida died, teachers regularly patrol the schoolyard each morning performing komoshido, or "gate guidance," inspecting uniforms and bookbags and hurrying students along. Other students said that if they arrive late, or fail to leave school promptly at day's end, they must run laps. If they take too long running, they have to run again and are not allowed to go home until they satisfy the teachers.

One student told Kume's news program on the Asahi Broadcasting Network that just before Ishida was crushed by the gate, he heard one of the teachers shout, "Forty-five seconds to go! Today I will definitely shut the gate!" Another student said that students' clothing and bookbags had been pinned by the heavy, fast-rolling gate in the past. On Friday, principal Nomura held a news conference to announce that from now on the iron gate will not be shut until 9 a.m.

"I gave guidance to not be late because that is a way for students to regulate their lives," he had said earlier. "But the way the door was shut could be too rough. I think it can't be helped but to rethink our guidance to latecomers."

Special correspondent Shigehiko Togo contributed to this report.