Ｍokoshi (a roof structure) (裳階)
Mokoshi is a small roof-like structure attached to walls under eaves in Buddhist halls, Buddhist towers or tenshukaku (keeps or towers of castles).
Summary
Ordinarily, a mokoshi is attached so as to provide another roof under the primary roof. It is also written as 裳層. Originally, it may have been used to protect the building from rain and wind. Its structure is simpler than that of the primary roof. This structure makes the building look like it has more floors than it really does, and therefore its use is effective for improving the graciousness of the building's outside appearance.
Therefore, this structure was favored especially in shrine and temple buildings
Examples of such buildings
The main hall and five-storey pagoda of Horyu-ji Temple
The east and west towers of Yakushi-ji Temple
Daibutsu-den (the Great Buddha hall) of Todai-ji Temple
Other names
Yuta (literally, beaten by rain)