The purpose of this study is to clarify how the consumption Citrus unshiu, a popular fruit in modern Japan and regarded as an important item in Japanese agricultural policy, became widespread.

Today, Japanese people eat various fruits. Citrus unshiu, which is easy to peel and is seedless, is one of the most popular fruits among the Japanese. In the Edo period, however, people did not eat it. They preferred Citrus kinokuni, a different variety of Citrus unshiu having seeds. Despite there being a seedless mandarin orange, the Japanese chose the seeded one because they believed that the presence of seeds would ensure the prosperity of their descendants; they considered Citrus kinokuni as a good luck charm and saw the seedless Citrus unshiu as an unlucky fruit.

After the Meiji era, Citrus unshiu began to be cultivated in various parts of Japan, and more and more people started eating it. In modern Japanese agriculture, Citrus unshiu is regarded as a highly economical and important agricultural product because of its wide area of cultivation and large quantity of production; therefore, Citrus unshiu is an important topic in geography and economics.

This research focuses not only on the production and distribution of Citrus unshiu but also on people's perception of it; it clarifies why Citrus unshiu, which was perceived as an unlucky fruit, has spread since the Meiji era.