Mie Castle was built on the northern mouth of Naha Port in 1546 by King Shō Sei.

[1] It was built to defend the Port and city of Naha, alongside its sister Yarazamori Castle.

Between the two castles, an iron chain boom-net could be drawn up to deny ships access to the harbor.

[1] These defenses were intended for use against pirates, however they proved successful in driving away the fleet of Satsuma during their 1609 invasion.

Originally, the castle was built in the middle of the water, with a long causeway connecting it to the mainland.