The Diet enacted a bill Friday to prevent increasingly serious bullying cases at elementary to high schools.
The move came in the face of a series of bullying cases, including a high-profile one in which a junior high school student killed himself in October 2011 in Otsu, Shiga Prefecture, after being severely bullied.
Under the newly enacted law, bullying that causes serious physical and mental damage to victimized children or forces them to be absent for long periods of time is defined as constituting a "serious situation."
Schools are required to report to the education ministry as well as local governments if such cases are confirmed, while investigative panels should be set up under schools and education boards to examine the details and provide sufficient information to the victims.
The law also says the state and local governments need to closely monitor the Internet for online bullying and cooperate with police if bullying activity is considered criminal.
The bill was jointly compiled by six ruling and opposition parties, and approved by a plenary session of the House of Councillors.