Originally an oil merchant, the dealer/exporter Imura Hikojiro of 22 Honcho Dori, Yokohama, became interested in the flourishing Tokyo etsuke (ceramic-painting aimed at export) trade and set up a business in Yokohama in about 1878. It is said that he came to own no less than four factories, with more than thirty ceramic-painters and over 200 workers. See Hida Toyojiro 'Exporters of Meiji Decorative Arts', in Oliver Impey and Malcolm Fairley (eds.), The Nasser D. Khalili Collection of Japanese Art (London, 1995), vol. 1, Selected Essays, pp. 70-95, especially p. 88 and Kanagawa Prefectural Museum (ed.), Yokohama dohanga [Yokohama prints], p. 224.
The name Shoun was used by the third of the Shimizu (Kiyomizu) Rokubei line of artists, who died in 1883. See Laurance P. Roberts, A Dictionary of Japanese Artists (Tokyo and New York, 1976), pp. 130-1.