OmushaOmusha, also umusa or umsa, was an Ainu greeting ritual that, like the related uimamu, became a ceremonial—of trade—full of the political symbolism of subservience, to the Matsumae Domain.NameThe word is understood to derive from the Ainu u, referring to mutuality, and musa, translated and defined by John [Batchelor (missionary)|John Batchelor] as "to stroke the head in salutation".