差金

The sashigane is a slender black pole tipped with wire, used to make prop butterflies and small birds flutter through the air; in the puppet theatre it is the rod inserted along a puppet's arm to work its hand. By convention the operator is treated as invisible, and the audience sees only the creature's flight.

From this came the everyday idiom "someone's sashigane"—an act instigated by an unseen hand. A word for a piece of stage machinery became, unchanged, a word for the hidden mechanics of human affairs.

In present-day usage, beyond the period-drama line "Whose sashigane is this?", one hears sentences like "The surprise audit was apparently head office's sashigane"—spoken whenever an unexpected turn seems to have a director hidden behind it. It is a keen-edged phrase that intimates an unseen hand in a single word.

Among the plays in which the sashigane shines is Shunkyō Kagami-jishi, the dance in which one actor performs both the maiden Yayoi and the lion spirit. A work of the Shin Kabuki Jūhachiban, it is said to have been premiered in 1893 by Ichikawa Danjūrō IX—and its pair of fluttering butterflies remains a celebrated showcase of the sashigane operator's art.