Onoe Waichi II (尾上和市 1832-1878) was the grandson of Ichikawa Ebijûrô (市川鰕十郎 1777-1827) and the son of Onoe Tamizô II (尾上多見蔵 1799-1866). He was also the older brother of Onoe Ichizô (尾上市蔵). His earliest stage name was Onoe Shôkô (尾上松光), and in 1861 he took the name Onoe Shôkaku I (尾上松鶴) while performing in Kyoto. He specialized in male roles.
Onoe Ichizô (尾上市蔵), later named Ichikawa Ichizô III (市川市蔵 1833-1865) was the grandson of Ichikawa Ebijûrô (1777-1827) and the son of Onoe Tamizô II (1799-1866). He might have become a high-ranking actor, as he displayed improving skills in leading roles. By his final year, 1865, an Osaka hyôbanki (actor critique: 評判記) had already rated him jô-jô-kichi (superior - superior - excellent: 上上吉). Unfortunately, he did not live long enough to realize his potential, dying in Osaka when he was barely into his early thirties.
The Zama Shanai no Shibai (座摩社内芝居) was a shanai shibai (shrine theater: 社内芝居), the term used in Kamigata (in Edo they were called miyaji-shibai, "shrine-grounds theaters": 宮地芝居.) Since the Muramachi period (1336-1568) temporary theaters within or just outside the grounds of shrines and temples offered venues for stage performances. During the Tokugawa period the shogunate generally restricted kabuki and puppet theaters to the entertainment districts of the three big cities (Edo, Kyoto, and Osaka), but it occasionally sanctioned temporary stages at shrines and temples for special events, such as festivals, fund-raising drives, and public viewing of religious treasures. It also appears, based on surviving kabuki records, that the use of shrine stages for kabuki performances in Kamigata was a regular feature throughout much of the period. The puppet theaters also operated occasionally at shrines.
Sadamasu's print depicts Onoe Ichizô in his ô-memie (stage debut: お目見え also called "first stage" 初舞台) at four years of age, performing with his older brother Onoe Waichi II. The play, Sarugashima, was a katakiuchi (a revenge drama: 敵討).
It is most unusual for an actor print design to feature two very young brothers. The portrayal naturally accommodates their youth, as they are depicted with short, slightly chubby, boyish figures — very unlike conventional drawing of young-adult or older kabuki actors. Also of note is the practice of producing a commercial print for such a young actor who is making his debut in a lower-ranking shrine theater.
Former collection of Martin Levitz, New York, who amassed a fine collection of Osaka prints, some of which were illustrated in Dean Schwaab, Osaka Prints. New York, 1989.
References: Nojima Jûsaburô (ed.), Kabuki jinmei jiten (Biographical dictionary of kabuki). Tokyo: 1988, p. 191; Sadamasu web page