The influential Osaka artist Sadamasu, later in his career known as Kunimasu, was the leading artist in the development of what is often called the Osaka chūban style (chūban prints measure roughly 19 x 26 cm). Many of his prints show high quality of design and are sumptuously printed with metallic pigments, embossing, burnishing, overprinting and other tour-de-force techniques, equalled by only a small part of the oeuvre of Sadamasu’s contemporaries.
    Virtually nothing is known of the artist’s life and personal details. In a small number of old documents he is mentioned as a woodblock-print artist, and in a few cases there is some concise additional information available. For instance, in the third volume of Naniwa zasshi chimata no uwasa written by Heitei Ginkei and dated 1835, Sadamasu is mentioned as a master at ukiyo-e. The revised edition of Naniwa shogei tamazukushi, published 8/1840, lists Sadamasu as one of the four most famous designers of ukiyo-e bust portraits, alongside Ryūsai Shigeharu, Hasegawa Sadanobu and Utagawa Sadahiro. Around the beginning of the Meiji period (1868-1912) the historian Sekine Shisei wrote a short biography of Sadamasu. The author states that the artist was a wealthy householder in the Senba district of Osaka, who studied with the popular artist Utagawa Kunisada in Edo. According to the historian, Sadamasu had many pupils, offered guidance to several Osaka artists, and used his wealth to create his own school of print design.
    According to authors of some relatively recent publications Sadamasu was a shipbuilder and the son of a rich merchant. Although his exact status remains unclear, we may conclude that Sadamasu was a wealthy artist who not only used his money and artistic talents to produce prints of his own, but also to give guidance to Osaka artists.
    The artist’s personal particulars, including several names that are found in the signatures and seals appearing in his oeuvre, are listed below.