Jûnishi (十二支) are the twelve signs of the zodiac, represented by the following animals: (1) ne [子]: rat; (2) ushi [丑]: ox; (3) tora [寅]: tiger; (4) u [卯]: hare; (5) tatsu [辰]: dragon; (6) mi [巳]: serpent or snake; (7) uma (午): horse; (8) hitsuji [未]: goat; (9) saru [申]: monkey; (10) tori [酉]: cock; (11) inu [戌]: dog; (12) i [亥].
The jûnishi provided a readily adaptable framework for print designs, especially in series, as here. Oftentimes, the animal signs were combined in clever ways with a great variety of subject matter. In Hirosada's series, the role names or dramatic plots were linked to the zodiacal animal. For example, in Hirosada's first design, which is associated with the sign of the rat (ne), the character Nikki Danjô had supernatural powers and could transform himself into a rat.
The actors and roles identified above were in the following productions (right to left, top to bottom): (1R) Meiboku sendai hagi; (2R) Sugawara denjû tenari kagami; (3R) Kokusenya kassen; (4R) Katakiuchi ura no asagiri; (5R) Nippon daiichi mekari no jinji; (6R) Tôkaidô Yotsuya kaidan; (7R) Koi nyôbô somewake tazuna; (8R) Azuma namari koi no Fukagawa; (9R) Shinshu oroku kushi; (10R) Sugawara denjû tenari kagami; (11R) Sangoku daiichi nochi no kusemono; (12) Kanadehon chûshingura.
The present group appears to be mitate-e, portraits of actors in roles or performances not recorded in kabuki records and thus probably imaginary.
References: IKBYS-IV, no. 130