The purpose of the group is to study the properties of magnetically confined fusion plasmas in the aspects of equilibrium, stability and nonlinear dynamics by means of theories and numerical simulations based on the fluid models. We mainly analyze the physical mechanism of the phenomena observed in the LHD experiments. In the analyses, we investigate the stability limit of the plasma and the effective particle supply method through the research of self-organizing phenomena, disruptive phenomena, magnetic island effects due to error fields, pellet ablation phenomena. Simultaneously, we develop the model equations and the numerical codes to involve more realistic conditions and we pioneer a new paradigm in the fluid plasma physics. The new knowledge is utilized for the improvement of the original understanding and the investigation of new mechanism for mysterious phenomena. By organizing the research results, we aim to construct a comprehensive theory over the whole toroidal plasmas. Foe this aim we also take the relation with other models such as transport physics into account.