Abstract
From the eleventh century to the twelfth, many Amidados were built. More than half of them were three-bay-square halls. Few buildings of this type had been built by this time. What is the reason for the rapid increase in their construction? There are two reasons : the first and major one is that it was the smallest hall with a formal style; and the other and less important reason is that it coincided with the form of the Jogyodo, a hall which was formerly thought to be the prototype of the Amidado. In order to go to Jodo, a Buddhist heaven, after one's death, it is necessary to perform pious acts. For example, an aristocrat should build a Buddhist hall. The three-bay-square hall was the easiest type to build since it was the smallest hall with a formal style.
