Roofs

One of the distinctions between Japanese and European castle roofs is a feature of decoration; the Japanese used gables to decorate the edges of their roofs. Chidori hafu (plover gables) and kara hafu (exotic gables) were triangularly shaped. Historians have reason to believe that the extensive decorative features of Japanese castle roofs were used as a form of defense . The gables on the roof confused the enemy because they would have trouble determining the number of levels the tenshu had. It was also difficult to tell the number of towers the castle had.

Until the Edo Period , the roofs of principal buildings in the castle compounds were made of cypress bark, but because of the increasing number of buildings, the wood was eventually substituted with copper and clay tiles. This was to protect the building from fires. With the growing number of buildings, if the roofs remained made of wood, fires would grow much more rapidly. Fire was one of the main reasons for building destruction. In 1657, the Edo Castle was rebuilt after a fire, and that was when its roof was covered with copper tiles. In the Nijo Castle , clay tiles were used on the roofs of the Ninomaru Palace, the kitchen building along with its adjacent buildings in the Nijo Castle compound.

A pair of dolphins made of tiles can usually be seen on Japanese castle roofs. These pair of dolphins are called shachi. One of the pair would be male and built on one side of the roof, while the other, a female, would be placed on the other side. The Japanese were very scared of the fires and susceptibility of their wooden castles that the shachi were built on top of the whole tenshu and many other parts as protection. The shachi were believed to be guardians angels of the castles.