Qualification that a leader should satisfy in managing nonprofit organization (NPO) is revealed by integrating the analysis of questionnaire survey and E-mail archives. Questionnaire survey is applied to 104 staffs in dot-jp, a specific nonprofit organization in Japan. E-mail archives are analyzed by applying the IDM (Influence Diffusion Model) that measures the influential relationships between staffs. The results of this paper conclude that a leader should catch staffs' messages as well as throw messages to construct trust relationships. Otherwise, the leader become self-righteous, and make staffs complaint about the organization.