Tsurugajo Castle is believed to have originated when Ashina Naomori built the Higashi-kurokawa-yakata castle in 1384.
The castle tower was later built by Gamo Ujisato.
Tsurugajo castle was once an impregnable fortress that endured an intense battle, which lasted about one month, during the Boshin War (1868-1869).
It was torn down by the Meiji government’s orders but was rebuilt in 1965.
In 2011, its roof tiles were changed to red to restore the appearance it had at the end of the feudal period.
It is a national historic site.