Sanshusha is a printing company with over 100 years of history. It was Sanshusha that printed the magazine Shirakaba, which is indispensable in the history of Japanese literature. For that reason, it seems that literary figures such as Saneatsu Mushanokoji, Naoya Shiga, and Takeo Arishima often went to "Sanshusha" to proofread their manuscripts.