In recent years, the problem of bullying in the classroom has been highlighted in the media.
There　is a need to prevent bullying at an early stage, or there is the dander that victims of bullying might face serious crises. Therefore, tackling the problem of bullying from the perspective of advanced prevention is important. Moreover, peer support activities, such as peers helping each other, as an educational activity have been focused as an effective method for preventing bullying. A review of empirical studies on the prevention of bullying and peer support activities conducted in Japan and overseas is presented.