RKH Architecture is currently prime consultant for the preservation of the Nikka Yuko Japanese Garden in Lethbridge, Alberta. Upon opening the ceiling to gain access to the attic space for structural corrections to the roof structure a "Johtoshiki " (ridgepole raising ceremony) was found. This is being treated as an important "character defining element" and that retaining its integrity is critical to the conservation of the Garden's Heritage value.
I contacted Mas Sugimoto (supervising architect of garden construction):
Some masks in the attic space that you ask to me is one of the ceremony and it calls ridgepole raising ceremony ("Johtoshiki " in Japanese).
I explain little about the ceremony.
This ceremony started at Heian era (about 8 centuries).
The ridgepole raising ceremony will be held when finished the framework of woodwork. And the meaning of this ceremony is thanks for finished the ridgepole raising and plays for this building will be safely after completion. This ceremony will be held for all buildings (wooden and concrete) in Japan.
The masks which you discovered are called "Okame" in Japanese. The Okame is name of head carpenter's wife and she suggested to his husband for his mistake. As a result of that his job was success but Okame committed suicide before the ridgepole raising ceremony to prevent it from becoming known that it was the suggestion of a woman that allowed this important task to be accomplished. After this happened her mask "Okame" was put together with other things for the ceremony
Another description
The architect of the Hondo was Nagai Takatsugi who, unfortunately, miscalculated the measurements for the main pillars and came up with posts too short. It was his wife Okame’s suggestion that saved his reputation; she proposed adding brackets to the top of the posts to reach the correct height. This was done, but Okame died before she could see the success of her proposal. When the last beams were put into place, the workmen, in her honour. Placed a mask of her round, plump, cheerful face on the ridge pole. Thus the cult of Okame began and spread throughout Japan, and she became the deity of good luck, the grantor of desires and patroness of business prosperity. As a mask, her round face has red cheeks and small, round eyebrows. In her honour, a statue of Okame sits to the right of Hondo when one faces the building.
Hondo (Main Hall) was built in 1227.
