Bannaji Temple

Bannaji Temple, located in Ietomi-chō, Ashikaga City, Tochigi Prefecture, is the head temple of the Shingon-shū Daijihā (Shingon Buddhism Daiji sect). The temple stands on the former residential grounds of the Ashikaga clan and is designated as a National Historic Site of Japan under the name “Ashikaga Clan Residence Site (Bannaji Temple).” Its main hall is designated a National Treasure, and the site is also listed among the Top 100 Japanese Castles.

The temple’s full name is Kongōzan Nio-in Hokkebō Bannaji, and it served as the clan temple (氏寺) of the Ashikaga family. Its principal deity is Dainichi Nyorai (Mahāvairocana Buddha). Originating in the medieval period, the temple was originally the fortified residence of the Ashikaga clan. Even today, it retains the traditional samurai residence layout from the Kamakura period, with gates on all four sides, surrounding earthen embankments and moats.

Bannaji is also known for the traditional event "Yoroi-Toshikoshi" (New Year Armor Parade) held during Setsubun. This event is said to have originated in the Kamakura period, when Ashikaga Yasuji gathered 500 warriors at this site. It was revived in 1915 (Taisho 4) by local textile merchants as a samurai parade and continues to be an important folk tradition.

The Main Hall is built in irimoya-zukuri style (hip-and-gable roof) with tile roofing, measuring five bays both in width and depth (note: “ken” is a traditional measurement based on the spacing between pillars, not a fixed length). The original structure was built in 1299 (Shōan 1), but underwent major reconstruction between 1407 (Ōei 14) and 1432 (Eikyō 4), during which all pillars were replaced and a worship hall (kōhai) was added at the front.

Its floor plan includes two front bays as the outer sanctuary, and three rear bays forming the inner sanctuary and side altars, typical of esoteric Buddhist (mikkyō) temple architecture. The architectural style is predominantly Zen style (zenshūyō), featuring dense tokyō (bracket complexes), onigawara-style base columns, latticed karahafu doors, and vertical plank walls. It also incorporates traditional Japanese elements such as coffered ceilings and wooden flooring.

The Main Hall is considered one of the earliest examples of Zen-style Buddhist halls in esoteric temples, and a rare early Zen-style structure in the Kantō region, making it of exceptional historical and architectural significance. It was designated a National Treasure of Japan in 2013.