Koanji Temple 髙安寺

Koanji Temple is of the Soto school of Zen Buddhism. The main structure was built in 1803, the temple gate was built in 1872, and the bell tower was built in 1856. The temple is designated by the Tokyo government as a historic building.

The temple was originally known as Shisenzan Kenshoji Temple, but after Shogun Ashikaga Takauji (1305–1358), the first shogun of the Muromachi shogunate, contributed to renovating the facilities, it was given the name Ryumonzan Koan Gokokuzenji Temple. The "ko" in the temple's name is an alternate reading of the "taka" from Ashikaga Takauji's name.

The site of Koanji Temple today is said to be on the remains of the residence of Fujiwara no Hidesato, the Governor of Musashi Province, who defeated Taira no Masakado. Takauji had Ankokuji temples and Rishoto towers built all over the country as an expression of his wish for peace for everyone. According to one theory, Koanji Temple is the Ankokuji temple of Musashi Province. Due to serving as a transportation hub during the period from 1337 to 1392, it became a war-time encampment for Kamakura Kubo Ashikaga, a high-ranking government official and Takauji’s descendent. During the Sengoku period (1467-1590), this property was exempt from standard residential area taxes known as munebetsusen from the Odawara-Hojo clan, and the distinctive goshuin seal from those times can still be seen at the temple today.