Seigakuin is a Shugendo (mountain ascetic tradition) Tozan-ha temple located in Sakai Ward, Sakai City, Osaka Prefecture. Founded in 1573, it was registered as a National Tangible Cultural Property in 2002 and has been open to the public since 2011 as the Sakai City Machiya (Townhouse) History Museum Seigakuin. It is one of the few surviving Shugendo temples that existed within an urban area during the Edo period. From the late Edo period to the early Meiji era, a terakoya (private elementary school) called “Seikodo” operated here, teaching commoners’ children reading, writing, and abacus skills in a flexible learning environment. The museum is also known as a place where Ekai Kawaguchi studied—famous for being the first Japanese person to cross the Himalayas and enter Tibet in search of Buddhist scriptures. At the terakoya, textbooks such as the “Thousand Character Classic (Senjimon),” “Tang Poetry Selections (Toshisen),” and “Orai-mono” were used, along with arithmetic texts and locally oriented materials teaching characters through Sakai’s place names, occupations, and shop names. Inside, visitors can see recreations of the terakoya setting and tour the Fudo Hall, where the principal image Fudo Myoo seated statue is enshrined alongside Kobo Daishi, Shomen Kongo, En no Gyoja, and Rigen Daishi Shoho—said to be the founder of the Tozan-ha tradition.