A human rights group said Japan has failed to protect its lesbian, gay, bisexual and transgender (LGBT) students.
Human Rights Watch said in a report -- titled "The Nail That Sticks Out Gets Hammered Down: LGBT Bullying and Exclusion in Japanese Schools" -- that bullying in Japanese schools is "widespread and brutal."
The report released Thursday said LGBT students are among the most vulnerable to bullying, but "the government policies addressing bullying do not specifically address the issues of LGBT students."
Japan has a national bullying prevention policy, which is up for review this year.
The 84-page HRW report is based on dozens of interviews with LGBT students and young adults across Japan.
One lesbian junior high school girl, accused by her classmates of not being "girly enough," said she endured repeated beatings from her fellow students that her teachers witnessed.
"It was common knowledge that I was being bullied," the girl said. "It was also common knowledge that my teachers would never help me."
LGBT students said their teachers often told them that by being openly gay or transgender, they were being selfish and should expect not to succeed in school.
HRW said it found a wide range of teachers' responses to student bullying. The rights group said a teacher's response depended on the individual teacher's opinions of the LGBT community.
Kannae Doi, HRW's Japan director, said, "No child's safety or healthy development should depend on a chance encounter with a compassionate adult. ... The government has a responsibility to train teachers to react to cases of bullying on the basis of sexual orientation and gender identity, and to protect LGBT students from harassment and discrimination."