The current research aims to analyze the discourse of the Japanese mainstream media about the war between Israel and Hamas on behalf of the Palestinian nation (in the period of 2023-2024), focusing on four media; NHK, Sankei, Mainichi Shimbun and Niki Media Group are the role and interaction of Japan's national development model in designing the approach and messages of international communication of this country. In this article, the theory and theoretical approaches of idealism in international communication, research on the formation of Japan's national development model and the social construction of reality have been applied. To achieve the purpose of the research, the practical model of discourse analysis (PDAM) has been used. For this purpose, in order to reach the theoretical saturation level, 60 texts from the 4 mentioned media were subjected to discourse analysis at five levels. The findings of the analysis of 41 basic signifiers of media discourses around 4 themes; 1.Paradigmatic propositions influenced by idealism in international communications, 2. USA and international political institutions, 3.Hamas movement, Iran and resistance groups, and 4.Zionist regime's war strategy and performance. The research results show the evolution of media discourse in 2 time phases; 1. The first days of the war and 2.The intensification of the killing of civilians by Israel shows that the direction of the signifiers is from an approach of hope for the functioning of international law institutions in resolving the conflict towards a Reproduces critical approach to the effectiveness of these institutions and curbing Israel's inhumane behavior.