More than 80 percent of school-age children surveyed have both engaged in and fallen victim to bullying, the National Institute for Educational Policy Research said Friday.

The finding indicates that every child has the potential to become involved in both sides of bullying, the institute said, adding that it will compile a handout based on the survey results for circulation among teachers of all schools.

Bullying cases at elementary, junior high and high schools across Japan tallied by the education ministry stood at around 100,000 in the 2007 academic year, slightly lower than in 2006.