Hasedo Castle is located in the mountains in Hasedo, Yamagata, in Yamagata Prefecture. Although the castle makes an appearance in the 'Date Document', which was written in 1514, the exact date in which the castle was built, and by whom, is still unknown.

At the Battle of Dewa, which took place at the same time as the Battle of Sekigahara in 1600, the Uesugi's West army overcame the strongholds of the East army, castle by castle, until they reached Hasedo Castle. Shimura Mitsuyasu, one of the generals of Mogami Yoshiaki's army, defended Hasedo Castle, and withstood an attack by 20,000 soldiers of Uesugi's army with only 5000 men. While Shimura and his men endured the attack, the West army lost at the Battle of Sekigahara, forcing the Uesugi army to withdraw. In 1622, due to the Mogami kaieki (change of rank), the castle collapsed.

Hasedo Castle's location is on a small mountain some 229m high. Today, it is surrounded by rice fields, and is called Shiroyama. The ruins, located at the summit of the mountain, have become the Jyoshi Park. Hasedo Castle is a traditional castle, which has served as a major turning point in history.