This study of female students, who have worn Western clothes since their childhood, attempts to answer two questions: how conscious are female students about their own ethnic costumes, and how do those who often wear ethnic costumes behave? In July and August 2006, a written survey questionnaire as well as a verbal survey of Japanese and Thai female students aged 18 to 24 years old (η=203) were conducted. The students of both countries indicated that their own ethnic costumes are difficult to move in. However, they highly valued them for being “conspicuous,” “pretty,” and “well-matched for themselves.” Japanese female students think that their ethnic costumes have a “peculiar feeling” and cause them to feel “tense when they wear them.” Such feelings are presumably caused by the difficulty of putting them on and the fact that they are mainly worn on occasions of rites of passage. Meanwhile, Thai female students have no special feeling towards their own costumes like in Japanese, though they hold them in high regard. The personal character of Japanese female students who frequently wear ethnic costumes are those who enjoy “going to the sea or mountains,” are “sensitive to fashion,” etc. They have active lifestyles. In Thailand, those who enjoy wearing their national costumes are “fond of reading,” are “leading a well-regulated life,” and are “helping their parents.” The female students of both countries are proud of their own traditional culture and wish for it to be preserved.