The number of bullying recognition at school is increasing every year, and it is a very serious problem in Japan. It is said that the cause of bullying is attributed to the fact that students have independent values in groups and they interact in a complicated way. In this research, we added some special agents into the agent-based model of bullying, and verified what behavioral characteristics are most effective in suppressing bullying by using multi-agent simulation. As a result, it was found that the behavioral characteristic “take the tuning action to an agent with a small number of selected values when the number of bullying candidates exceeds the threshold value, and take the tuning action to an agent who is a bullying candidate when the number of bullying candidates is less than or equal to the threshold value” of special agents is most effective in suppressing bullying.