Hitsujisaru Yagura is a reproduction of a wooden gate built at Sunpu Castle in the early 17th century. Its hip and gable roof design is called irimoya-zukuri. Although Higashigomon (East Gate) looks decorative, it was designed for battle. The façade includes narrow arrow slits (ya-sama) plus openings for muskets (teppo-sama) and cannons (taiho-sama). Assuming an enemy reached the moat, they were pummeled by falling stones hurdled from roof slats called ishi-sama. No wonder the Japanese named a castle entrance koguchi meaning “tiger’s mouth.”
