This paper outlines a new educational framework for the Judo curriculum established through development of a scale designed to evaluate a pattern of tactical thinking, “the principle of Ju”, inherited from Jujitsu and Judo through a study of Japanese traditional culture in schools. First, we developed a hypothetical concept for evaluating “the principle of Ju”, which is based on the basic movements and tactics whereby “softness overcomes hardness” (ju yoku go wo seisu), as outlined in “the principle of Ju”. We devised a 35-item evaluation scale and investigated it in detail using the Delphi method. We then formulated a questionnaire comprising 28 items. Next, we subjected Jujitsu practitioners and Judo athletes to exploratory factor analysis and verified the adaptability of a factor analysis model and the reliability of the scale. This research approach yielded two findings: 1) There are two principle elements of ancient Japanese martial arts, kisoku wo hazusu ugoki (lit. A fluid shift between anticipatory restraint and counter-movements.) and in to yo no tsukaiwake (lit. A yin and yang approach of selecting actions which harmoniously counter-balance those of the opponent). 2) “The principle of Ju” is able to provide a realistic Judo class and curriculum for learning practical movements and tactical decision-making in schools. Then, through a comparison between wrestling athletes and the general concept of “the principle of Ju” in modern society, it has been clearly confirmed that this is inherited by Jujitsu practitioners, whereas Judo athletes exhibit this on the same level as wrestling athletes. These results indicate that Judo has been influenced by athletic sports, and that this has now become an essential part of Judo principles. Accordingly, “athletic Judo” appears to have a limiting influence on the Judo curriculum when studying traditional culture in schools.