In the old days these were often built in the form of window rooms in the upper storey of large roofs in which it was difficult to make a window opening (hafu room) and through the ages these have mostly simply become decorative features with no room behind in the roof.
古くは、大きな屋根などで、窓の開口が難しくなった階層などに出窓のように突起して屋根を被せたもの(破風部屋)で、時代が下がるにつれて単に飾りというだけのものとなり、小屋裏に部屋さえも持たなくなることが多くなった。