MATSUI Ryugo has been researching the cross-cultural phenomenon based on the study of comparative literature and culture. He has especially been interested in the life of the people who created innovative literary or philosophical works after having experienced the encounters with different culture. Though his main accademic publishments are concerning MINAKATA Kumagusu (1867-1941), he provides with the study of various examples of such people who had the experiences across the border of different cultuers to the students.