This paper reports on three studies of the existing medieval gyokuden (inner sanctuary) in the main shrine of Miyayama-hachiman Shrine in Misonou Saijo-cho Higashihiroshima City, Hiroshima Prefecture.
1. Detailed architectural technique was revealed by the survey of the gyokuden, which has been previously unidentified.
2. Characteristics of the gyokuden and the date of its construction were determined by comparing the design and techniques of this gyokuden with those of medieval gyokuden in Aki Province.
3. The history of the restoration of the gyokuden and its relationship to the shrine was clarified from historical records.
From these, we have concluded that this gyokuden was built in the early 15th century because, despite its small size and the small size of the misedana, many ancient features such as the shape of the roof, the presence of the misedana, and the design and technique of the gyokuden were identified.
By restoring this gyokuden to its original state, it was found that the shrine was in the form of nikensha and two deities were enshrined at the time of its creation. The present roofing materials and changes of the gyokuden can be explained in accordance with the history of the shrine after its establishment.