A fluidic torque transfer device is configured such that the attachment angle of a turbine blade at a fluid outlet of a turbine runner is smaller than the attachment angle of the turbine blade at a fluid inlet of the turbine runner. Furthermore, the turbine runner is structured so that a cross-sectional area St of a turbine flow path defined by the turbine shell, adjacent turbine blades, and the turbine core, which is perpendicular to a centerline of the turbine flow path, satisfies |St−Sref|/Sref≦0.2, where a reference area Sref is an average of maximum and minimum values of a cross-sectional area of a pump flow path defined by the pump shell, adjacent pump blades, and the pump core of the pump impeller, which is perpendicular to a centerline of the pump flow path.