Originally built in the 1400s, the official name of this castle is Nihonmatsu Castle. Some 4,500 somei yoshino and wild yamazakura bloom here, giving the impression that the castle is veiled in a sakura haze. This is how the castle acquired its name Kasumigajo (kasumi means haze). The Niwa family ruled the castle from 1643 until the Meiji Restoration. It became a park in 1948 and is a designated national historic site.