The temple of 東禅寺 (Tōzen-ji) occupied a pointed position at the edge of Edo's Takanawa district, its gates opening directly onto the 東海道 (Tōkaidō) — the road that connected the capital to the rest of Japan. When the shogunate assigned it to the British legation in 1859, the choice was arguably reckless: this was not a hidden compound but a landmark, visited by pilgrims, visible to every traveler entering the city from the south.

Sir Rutherford Alcock, the British Minister to Japan, was not an easy man to intimidate. He had recently completed an overland journey from Nagasaki to Edo, traveling the interior roads despite the shogunate's explicit requests that he go by sea. To the radical sonnō jōi (sonnō jōi) movement — men who believed foreign contact was a civilizational poison — that journey was a calculated insult. Alcock was not merely present in Japan; he was parading through it.

The men who came for him on the night of July 5 were 浪士 (rōshi), masterless samurai, former retainers of the Mito domain. Mito had been the ideological heart of anti-foreign sentiment for decades — its scholars had articulated the sonnō jōi philosophy most forcefully, and its young men had taken that philosophy into the streets with swords. Their leader that night was Ariga Hanya, a committed radical who had planned the attack carefully and chosen the hour of darkness.

What the attackers encountered inside the gate was not chaos but resistance. The legation's guards — Japanese men in the shogunate's service — stood their ground. The fighting was close and lethal. Three attackers were killed, including Ariga. Two defenders died. The writer Laurence Oliphant, present at the legation and soon to become famous for his travel writing, was wounded. So was diplomat George Morrison. The raiders who survived were captured.

Alcock's response was cold and swift. He declared the site indefensible, wrote that he no longer trusted the Japanese government to protect his mission, and moved the British legation to Yokohama — a port city the shogunate could at least surround with friendly ships. The diplomatic fallout spread across European newspapers, where the story was read as proof that Japan's open-ports experiment was built on sand.

In Edo, the deeper irony was not lost on thoughtful observers: the most committed 攘夷 (jōi) attack of the Bakumatsu period had been defeated not by foreign soldiers but by Japanese ones, defending a foreign legation on Japanese soil. The two Japans had met at the gate of Tōzen-ji and fought each other to a bloody draw. The walls of the temple still carry the scars — sword nicks carved into the wood, bullet holes in the plaster — a record no one thought to repair.