The kuangyan qiyu (wild words and flowery expressions) as a popular literary style prevailed during the mid and late Tang Dynasty. Textual research shows that Bai Juyi (AD 772-846), one of the great Tang poets, is the first man who used the kuangyan qiyu as a literary term. From the first year of Japan’s Kouhou reign (AD 964), this concept of his was accepted by the representative groups of Japanese literati, gradually becoming an important trend of thought in art and literature in the middle and late Heian Period and ultimately the mainstream in Middle Ages. It also made some considerable impact in Japan in modern times. Although the kuangyan qiyu did not go down history as a literary concept in China, it is necessary for us to trace its origin and study the background of its emergence so that further research can be made into the reason why it has exerted such a widespread and profound influence on Japanese art and literature.In the 4 th and 5 th year of the Kaicheng Period of Emperor Wenzong of the Tang Dynasty (AD 839-840), Bai Juyi advanced the concept of kuangyan qiyu . From his point of view, the kuangyan qiyu could find expression in poems and prose whose writers did not confine themselves to the accepted rites but indulged in wild words and sensual pleasures. Nevertheless, while examining his “wild words and flowery expressions” that could supposedly violate Confucian tradition and Buddhist disciplines, Bai Yuji confirmed the reasonableness of the kuangyan qiyu by complying with his original wish that the “non religious language” and the “ kuangyan qiyu ”, taken as “Karma” and “demerit” respectively, should serve to disseminate Buddhism constantly.The emergence of the kuangyan qiyu was due to the new prevailing custom of the Tang Dynasty. The unification of the country, the unity of different ethnic groups, the stability of the society, and the free, active and relaxed ideological environment all contributed to the formation of the new custom characteristic of sensual pleasures as its superficial phenomenon. In this context, therefore, the Southern Chan School became popular and Mizong (Esoteric Buddhism or Tantrism) came to appear. While the Southern Chan School advocated that “being natural to its extreme” should be a person’s ultimate ideal of life, which served as the general guiding principle of Chinese literati and scholar officials for their attitude towards life, Mizong advocated the “interdependence between pollution and pureness” and “becoming pure hearted by being exposed to pollution”, which also had great influence on people’s attitude towards life. These two Buddhist schools pushed forward the development of the new custom and vice versa. From a certain perspective, it was the new Tang custom, the Southern Chan School and Mizong that facilitated the growth of the kuangyan qiyu.
