Koromo Castle, Japanese mountain castle in Toyota, Japan

Koromo Castle, also called Shichishū-jō, was built in 1782 on the 65-meter hill Dojiyama in Toyota. Its grounds now hold the Toyota Municipal Museum of Art and the Toyota City Museum, which opened on 26 April 2024. A stone wall of the corner yagura base remains, and the corner yagura was rebuilt in 1977. Next to it stands the Yūjitsutei, a former temple study moved here in 1977.

Naito Masamitsu ordered the fortification built in 1782 after taking control of the Koromo domain. It stood through the late Edo period until the Meiji Restoration brought an end to the feudal system in the latter half of the 19th century.

The castle's name, Shichishu-jo, comes from the seven provinces visible from its donjon: Mikawa, Owari, Mino, Shinano, Tōtōmi, Ise and Omi. The Naito clan resided here until the Meiji Restoration. A storehouse for the floats of the Koromo Festival reuses timber from dismantled castle buildings.

The grounds are open and free to enter as part of the Toyota Municipal Museum of Art. A preserved section of the original moat runs alongside the site and gives a clear sense of how the fortification was once defended.

The name Shichishu-jo comes from the seven provinces visible from the donjon: Mikawa, Owari, Mino, Shinano, Ise, Omi and, in the Japanese account, Iga; the English source instead lists Totomi. The hill, Dojiyama, rises about 65 metres above the former Miyake residence.