Kōraiya

The Kabuki Encyclopedia's entry on the Matsumoto house records a long and close relationship with the Ichikawa Danjūrō family: Kōshirō II later became Ichikawa Danjūrō IV, and Kōshirō III later Danjūrō V, while Kōshirō VII was a pupil of Danjūrō IX. It is within that connection that the name Ichikawa Somegorō is carried by this house.

The same entry notes that Kōshirō VII is said to have played Benkei in Kanjinchō more than 1,600 times, and Kabuki-bito records that the role has passed through four generations of the house from Kōshirō VII to the present holder. Kanjinchō is a play the Naritaya house fixed among the Kabuki Jūhachiban in the time of Danjūrō VII; the art of Kōraiya has been laid over it.

The Encyclopedia records that Kōshirō VII's second son succeeded as Kōshirō VIII and in later life took the name Matsumoto Hakuō I. According to the Kabuki Actor Directory, Matsumoto Kōshirō X and Matsumoto Hakuō II took their names at the Kabukiza in January–February 2018; the official Matsumoto Kōshirō site records that the present Ichikawa Somegorō is the eighth of that name.

As for the origin of the house name: the Kabuki Encyclopedia notes that the origins of yagō in general are not clearly known, and this site leaves this house's unstated until a primary source confirms it.