The foundation and purpose of museums differ, as results, their methods of acquisitions, exhibitions and other activities differ because of the different management styles of founders, managers, acquisitors (or collectors). This paper takes Okada Mokichi (1882-1955), the original founder of MOA Museum, as an example, describing the spiritual condition in his life history, classifying the new religious dogma he leads, and analyzing the concept of Japanese art he wanted to pursue or establish. Even though, the establishment of the museum was only the one of his plans creating miniature utopian world, under the idea of "aesthetic" may cultivate moral sentiments, he tried to select art objects which can meet this purpose; however, these objects do not includes idols or tales which Buddhism or Christianity emphasize. The author tries to view the background and accumulated concept of Japanese art as the center of Oriental art by Okada, and see how he engaged collection development work.