Buddhism was officially introduced into Japan in AD 552 from Paikche, a kingdom in Korea, but thirty years earlier Buddhist images had been brought to Japan. In 594 the Prince Regent, Shōtoku Taishi (574-622) declared Buddhism the state religion.

Buddhism at this time was quite devoid of the distinction of sects or schools, although the difference of Mahayana and Hinayana was clearly recognized. The Prince himself strictly adhered to Mahayana and wrote commentaries upon three Mahayana texts. The fame of these excellent annotations spread abroad, and one of them was chosen as a subject of commentaries by a Chinese savant.

The particular type of Mahayana that was adopted by the Prince may be seen from a consideration of the texts which were chosen. The first is the Lotus of the Good Law, a text devoted to the Ekayāna (One Vehicle) doctrine, indicating the idea of the good law. The second is the Discourse on the Ultimate Truth by Vimalakirti, a lay Bodhisattva of Vaisali, while the third is the Book of the Earnest Resolve by Srimala, a lady Bodhisattva, the Queen of Ayodhya. The central idea of this non-sectarian period was the doctrine of the Great Vehicle (Mahayana) as expressed in these three texts. This idea has remained the dominating feature of Buddhism throughout its history in Japan.