[1] One of the four great Zen temples of Edo, it is best known in history as the location of the first British legation in Japan during the Bakumatsu period and the site of a number of incidents against foreigners by pro-sonnō jōi samurai.

[2] [3] The temple was established in 1610 in Akasaka by Ryōnan Zenji, and its name comes from the Dharma name of Itō Sukenori, daimyō of Obi Domain in Hyūga Province (preset day Miyazaki Prefecture).

Japanese authorities were against the choice of Edo and advised Alcock to settle in Yokohama, especially as Tōzen-ji was located at the entrance to the Tōkaidō, the busiest and most important highway in Japan, and was therefore exposed to possible attacks.

Although the Shogunate had requested that he return by ship due to security reasons, he insisted on traveling overland to uphold one of the provisions of the treaty, namely that the movement of diplomats within Japan not be restricted.

Alcock, who had bitterly protested the presence of the Japanese guards as a nuisance and accused them of being nothing more than spies for the Shogunate finally realized the depth of anti-foreign sentiment.

He threatened that he would use the attack as a casus belli unless the shogunate agreed to permit a British garrison to be stationed at the legation, the number of Japanese guards increased, and compensation of $10,000 to be paid.

However, in May 1862, Lieutenant Colonel Edward St. John Neale who had assumed duties as Chargé d'affaires in Japan during Alcock's period of extended home leave ordered the legation to be returned to Tōzenji, pending the construction of a new purpose-built diplomatic compound at nearby Gotenyama.

One of the guards from Matsumoto, Itō Gunbei, was concerned about the expense his domain was incurring providing this security and about the possibility that he would be forced to kill fellow Japanese in order to protect the hated foreigners, so he decided to assassinate Neale himself.