Inuyama Castle

Inuyama Castle, located in Inuyama City, Aichi Prefecture, is an ancient Japanese castle situated on hilly terrain on the south bank of the Kiso River, at the border between the former Owari Province and Mino Province. Built on a hill about 88 meters high, it is a typical hirayama-jiro (hilltop castle). Due to its strategic location, it has been a key site for military and political control since ancient times. The castle was originally constructed as a fort by the Iwakura branch of the Oda clan and was later rebuilt by Oda Nobukatsu, uncle of Oda Nobunaga, forming the prototype of Inuyama Castle. It subsequently came under the governance of lords such as Ikeda Tsuneoki and Oda Katsunaga. During the Toyotomi regime, Ishikawa Sadakiyo further renovated the castle, establishing the basic layout seen today.

The castle played an important role in the Battle of Komaki and Nagakute and the Battle of Sekigahara during the Sengoku period, serving as a crucial stronghold for the Western Army. In the Edo period, it was garrisoned by Hiraiwa Chikayoshi, a hereditary vassal of the Owari Domain, and was later ruled by the Naruse clan for nine generations until the Meiji era. The Naruse family carried out multiple renovations, and it is believed that the current main keep (tenshu) was completed around 1617 (Genna 3). The tenshu of Inuyama Castle is one of only twelve surviving original Japanese castle keeps and is designated as one of Japan’s five National Treasure keeps, preserved in near-original form to this day.

One of the most remarkable features of Inuyama Castle is that it was the last privately owned castle in Japan. Until 2004, it remained under the ownership of the Naruse family before being transferred to the newly established Inuyama Castle Hakutei Bunko Foundation for management. In 2006, it was selected as one of Japan’s Top 100 Castles.

The main keep is of the watchtower style, appearing as three stories externally but containing four internal floors plus two underground levels. It features a traditional irimoya roof, with attached turrets on the south and west sides. The keep covers nearly 700 square meters and stands about 19 meters tall. Its stone walls are built using the “nozura-zumi” technique of stacking unshaped natural stones, with the base about five meters high. The windows vary in style, including projecting windows, katōmado (bell-shaped windows), and double-opening windows, reflecting architectural features from the late Sengoku to early Edo periods. It is said that the seventh head of the Naruse family once carpeted the top floor to receive distinguished guests—a detail restored during renovations in the Shōwa era.

Inuyama Castle is also known as “Hakutei Castle,” a nickname attributed to the Edo-period Confucian scholar Ogyū Sorai, who likened its position on a high hill overlooking the Kiso River to the “Hakutei Castle” described in the poetry of Li Bai, the Chinese poet. Today, from Inuyama Bridge over the Kiso River, the castle’s scenic setting—backed by hills and fronted by water—retains an air of antiquity, evoking memories of the samurai and the rise and fall of political powers.

In recent years, Inuyama City has actively promoted the restoration and preservation of the castle, including repairing the shachihoko roof ornaments and rebuilding moats and stone walls. In 2017, the shachihoko on the main keep was damaged by lightning; it was repaired the following year, with a commemorative ceremony held to mark the event. The castle was designated an Old National Treasure in 1935 and formally designated a National Treasure under the Cultural Properties Protection Law in 1952. It is currently managed by the City of Inuyama.