In various social situations such as elections or shopping, individuals are often persuaded in multiple directions by different sources (i.e., multiple-source-and-direction persuasion). In this paper, we discussed the attitude change process in this type of situation, based on two dual-process models of persuasion: (1) the heuristic-systematic model and (2) the elaboration likelihood model. These models assume single-source-and-direction persuasion and cannot be applied without modification to multiple-source-and-direction persuasion. Therefore, this paper focuses on the simultaneous consideration of multiple persuasive messages as a process particular to this situation. In addition, by using a concrete experimental design, we demonstrated in this paper how a hypothesized model accounts for a recipient’s attitude change. We emphasized the significance and the future prospects of clarifying the attitude change process in multiple-source-and-direction persuasion.