This paper aims to examine the ideas of Otsuka Taiya(大塚退野), the founder of the Kumamoto Jitsugaku School, who is said to be the most devoted to the scholarship and personality of Yi Toegye in the history of Japanese thoughts. He is the teacher of Yokoi Syonan(横井小楠), I have reviewed the acceptance of this school of Toegye Studies by examining the related texts of Motoda Nagazane(元田永孚) and tried to find out the desirable future of Korea-Japan relations through this review.\nDaiya chose and absorbed in the orthodox Neo-Confucianism of the Zhu Xi-Toegye among the various ideologies of the East Asian thought in the 17th and 18th centuries, and narrowly, in the Edo Periode Thought. And later, this was the basis for the later scholars of attempting the New Studies of Silhak and formed an important axis of the late Shogun period.\nIn this paper, the primary contacts and influences of Kumamoto Jitsugaku School Scholars and Toegye Studies were in the Mind Study(心學). And as a result of this work, we examined the scholars mentioning of Yi Toegye, including Ogyu Sorai(荻生徂徠) and the critical discourse of Jamazaki Ansai(山崎闇齋). The criticism between Sorai and Ansai also has a political meaning in the history of Japanese thought to reveal the location and the ideological character of the Toegye-Kumamoto Jitsugaku School.\nFinally, the emphasis of this MInd Study is linked to The Relationship Theory between Heaven and Human Being(天人合一論). Therefore it is suggested by the scholars of Kumamoto Jitsugaku School as Toegye and his successor that ‘the true heart’ related to the nations, and ‘the great moral principle(大道) of Heaven-Earth-Human-Rightness(天-地-仁-義), and they pointed out that the idea of a desirable future of Korea and Japan could be made not in the the fictional face and competition of nation , but on the extension of the true In (仁) policy of taking care of the real life of people.