Isonokami Jingū Treasure House

Isonokami Jingū, enshrined in Tenri City, Nara Prefecture, is one of Japan's oldest and most sacred shrines — and arguably the single most spiritually significant site in the entire history of the Japanese sword. Its Treasure House holds materials central to understanding the origins of nihonto, both material and mythological.

The supreme treasure is the National Treasure "Shichishitō" (七支刀, Seven-Branched Sword): an iron blade 74.9 cm in total length, with six lateral branch-blades projecting from the main blade — three to each side. According to the Nihon Shoki, this extraordinary object was presented by the Crown Prince of Baekje to the ruler of Wa (Japan) in 369 CE. The Shichishitō is simultaneously the most important artifact of ancient Japan-Korea diplomatic history and the oldest surviving metal sword object in Japan that can be dated with some precision, making it the indispensable starting point for any serious engagement with nihonto history.

The shrine also enshrines "Futsunomitama-no-Tsurugi" and "Futushimitama-no-Tsurugi" — divine sword-spirits named in the Kojiki and Nihon Shoki as weapons wielded by deities in Japan's mythological narrative of creation and pacification. These divine swords represent the conceptual origin of the sacred status the Japanese sword has held throughout Japanese cultural history.

The Treasure House displays a replica of the Shichishitō (the original is kept in strict preservation and not publicly exhibited), together with iron swords and blades from the Kofun period through the Heian period — offering a systematic view of the dawn of Japanese sword culture. The shrine precinct itself — where the divine chickens (神鶏) sacred to the deity roam freely — preserves an atmosphere of ancient sanctity that makes a visit here an encounter with nihonto at its deepest roots.