Yosino Mago Zenpen is believed to have been published in the early 19th century, likely around the Bunka-Bunsei era (1804–1830), a golden age for Bakin’s creativity. The title indicates it was conceived as a prelude ( zenpen ) to a larger story centered on a “grandchild” ( mago ) connected to Yoshino, a name resonating with imperial history. Yoshino, in Nara Prefecture, was a stronghold of the Southern Court during the 14th-century Nanboku-chō period (Northern and Southern Courts). Bakin frequently plundered this era for its dramatic potential, pitting legitimate imperial successors against usurpers. This work is thus a historical fiction, not a factual chronicle.

It seems you are asking for a proper report on a title that reads (possibly Yoshino Mago Zenpen ).