In this case Karafuto means the region and attached islands south of the fifty northern latitude on Sakhalin (so-called Southern Sakhalin), which was incorporated into Japan through the Treaty of Portsmouth.
この場合、樺太とは樺太の内、ポーツマス条約により日本へと編入された50度線以南の地域（いわゆる南樺太）及びその付属島嶼を指す。