The story of the 47 rōnin (masterless samurai) who (cleverly, murderously) avenged their master, Lord Asano – put to death after being tricked into pulling a sword on a rival – is legend in Japan. They were condemned to die, but allowed to commit seppuku (ritual disembowelment; an honourable death for a samurai) and their remains were buried at this temple. It's a sombre place, with fresh incense rising from the tombs, placed there by visitors moved by the loyalty of the samurai.
There is a small exhibition hall (adult/child ¥500/250) with artefacts and a video (available in English), which illustrate the story of the rōnin.