The small, close bedrooms discussed in the last few posts, though certainly ‘specialised’ as sleeping spaces, were also commonly used as storerooms for valuables, and sometimes this was their primary role; from the very first time rooms were partitioned off from previously single-space dwellings, there has been a close association between sleeping and storage. Even in the ancient residences of the nobility, the shinden zukuri (寝殿造り), a corner of the dwelling would be enclosed into a nuri-gome (塗籠), a storage room for valuables that was also used as a bedroom. The name nando (納戸) today refers to a storeroom or ‘walk in robe’; but it once also referred to a bedroom of this type. Often the only partitioned room in the dwelling, with solid, windowless external walls on two or three sides, an equally solid partition wall, often of thick timber boards, on the other interior sides, and a single small entrance, these rooms were the obvious choice for the role of ‘safe room’.
An illustration showing a nurigome (at lower left) in a classical shinden-zukuri residence. The design of the partition wall of stout battens and boards, and the closed board door with its kururu-gi bolt and hole to receive the ‘key’, and keyhole, are clearly visible.
The security of these rooms was completed with a type of lock (kagi 鍵) that adds a ‘key’ known as a kururu-kagi (枢鉤, ‘pivot hook’) and a keyhole (kagi-ana 鍵穴) to the basic sill bolt (otoshi-zaru 落し猿, ‘dropping monkey’; or, in this application, kururu-gi くるる木, ‘pivot timber’). The otoshi-zaru is perfectly adequate for locking a room or house against intruders from the inside when people are home, but it can only be operated from its side of the door, so can’t be used to secure an unoccupied room or house when one goes out; further, a ‘snib’ piece called yose-zaru (寄せ猿, ‘closing monkey’) is required to stop the otoshi-zaru from dropping into its sill mortise accidentally when the door is closed, potentially locking the inhabitants out. In the kururu lock, this drawback is turned into a feature: the yose-zaru is omitted and replaced with the kururu-kagi, so that when the door is closed it locks automatically, but the otoshi-zaru can be lifted, and the door opened, from the outside, at least by the person who has the kururu-kagi, but not by anyone else.
A sliding door with three timber bolts: top, an age-zaru (上げ猿 or 揚げ猿, ‘raising monkey’) with yose-zaru (寄せ猿, ‘closing monkey’); middle, a yoko-zaru (横猿, ‘side monkey’); and bottom, an otoshi-zaru (落とし猿 ‘dropping monkey’) or sage-zaru (下げ猿, ‘lowering monkey), with yose-zaru.
An otoshi-zaru bolt in open position. The otoshi-zaru is raised, but the yose-zaru hasn’t been drawn across to hold it in the raised position, suggesting that this door is open and the bolt is being held up by the sill. If someone closed the door from the other side without remembering to draw the yose-zaru across, the otoshi-zaru would drop into its sill mortise, potentially locking the person out.
An old kururu-kagi (枢鉤) on the left, and on the right a diagram showing how it is used to lift a sill bolt (kururu-gi 枢木) from the other side of the door. Also labelled is the door rail (san 桟) which holds the upper part of the bolt.
A scale model showing the inside face of a hinged door with an otoshi-zaru and ‘pivot lock’ (kururu-kagi 枢鉤) coming through the keyhole (kagi-ana 鍵穴), surrounded by an escutcheon (kagi-ana-tate 鍵穴盾). The end of the kururu-kagi has an elbow, and fits into a hole in the otoshi-zaru.
The outside face of the door, showing the handle of the kururu-kagi inserted into the keyhole. When the bent tip of the kururu-kagi is inserted into the hole in the otoshi-zaru and the handle of the kururu-kagi is rotated clockwise, it lifts the bolt out of its sill mortise (visible in this photograph), allowing the door to be opened.
Unlike a modern key, whose uniqueness lies in the arrangement of its teeth, a kururu-kagi is distinguished from other kururu-kagi by its length. Another random kururu-kagi might fit in its keyhole, but if it is too long or too short, it won’t engage with the hole in the kururu-gi. Though kururu-kagi are simple objects, fabricating one would require the skills of a blacksmith, and to make an effective copy a thief would need to know the distance between the keyhole and the hole in the kururu-gi.
The kururu-kagi normally stayed in the possession of the husband and wife; entrusting their daughter-in-law (yome 嫁) with it was an indication of their recognition of her ‘housewife’s rights’ (shufu-ken 主婦権).