Teachers at a public high school in Toyama Prefecture snipped the hair of at least 44 students last year to make it short enough to meet school rules, the school and local education board said Friday.
The haircuts, which the six teachers at Mizuhashi High School said were given from April onward with the students' consent, were "excessive," said Shinichi Hiroshima, a senior official of the prefectural education board, adding that the board will punish those involved if necessary.
The case came to light after the school was informed by outside sources. It questioned all teachers on the matter earlier this month.
The teachers cut the hair of all students who repeatedly broke the rules, which state that hair is expected to stay above the eyebrows. Male students cannot let hair cover their ears. Students' hair was checked on a monthly basis to make sure it met school standards.
"We do not have a school policy of cutting hair, and this should not have happened," said Principal Yasuhiro Nakada, who looks after 477 students. "I would like to apologize to the students and their parents."
Many Japanese schools have strict rules on fashion, including bans on hair dying, piercings and makeup, and there has been much criticism for the way the rules are over-regulated.
Last October, an 18-year-old girl in Osaka sued her high school for allegedly demanding that she dye her naturally light-colored hair black.