Yokan is an ancient Chinese imperial dish; it is prepared by steaming lamb stomach and intestines filled with peas and lamb in a broth. Japanese monks who studied in China introduced the Yokan technique to Japan. After several modifications, Yokan was transformed into a popular tea dessert in Japan. During the Japanese occupation, the dessert was introduced to Yilan, where cold spring water of the Suao was stewed together with locally produced agar and granulated sugar, and finally malt sugar and bean paste was added to form the finely textured and highly elastic Suao delicacy, Yokan.