The number of juvenile crimes caused by school bullying rose 57.7 percent to 410 cases last year, up from 260 cases a year earlier, according a report by the National Police Agency.
The NPA's Juvenile Division said Friday that the number of cases, including those related to retaliation against bullying, was the most since 1985, speculating that more cases were reported due to the scandal over a bullied junior high school boy's 2011 suicide in Otsu, Shiga Prefecture.
The number of people aged 14 to 19 who were arrested or taken into protection and guidance by the police due to bullying reached 724 in 2013, an increase from 511.
The NPA said they were made up of 527 junior high students, 109 high school students and 88 elementary school students.
Violence and infliction of bodily injury accounted for about 70 percent of all types of crimes related to bullying.