The company had a comparatively slower and more difficult time breaking into Japan's other major colony, Korea, which was formally annexed in 1905. Compared to Taiwan and Japan's home islands, per capital consumption of patent medicines was a paltry 162,491 yen for a population of 16,278,389 people (Misawa et al. 2008, 43). This was reflected in how the company characterized its efforts to sell medicines in Korea as a "pioneer movement" (kaitaku undō) that spread quality medicines to places rife with illness and poor quality medicines, which differed from how it characterized its efforts in Taiwan (“Kaitaku no noroshi heizen to kagayaku" 1924). Preparations for Hoshi's franchise system in Korea only began in late 1910s; in 1918, for example, the company dispatched an executive on a three-month fact-finding mission before beginning its expansion into the Korean Peninsula ("Takagi shucchōin Chōsen yori kikyō" 1918). Although it is unclear when, exactly, the first franchises appeared in Korea, the first general wholesaler (sōmoto urisabakusho) for the entire peninsula was established in Keijō (Seoul) in June of 1922, which, by the end of 1923, was in charge of eleven local wholesalers; the first franchise convention occurred in late May of 1924, simultaneously in Keijō (610 people), Kameyama (Pusan) (264 people), and Gunsan (288 people) (Misawa et al. 2008, 43).
Compare Hoshi's expansion in Japan's colonies to that of Mitsukoshi Department Store.