It's long been a rather cynical maxim of the Japanese movie business that, when all else fails, you can always put butts on seats with a revival of "Chushingura."
This venerable property, starting with dramatizations soon after the incident and continuing through countless iterations on stage, screen and television, is based on a true incident. In 1701, Lord Asano Naganori of the Ako domain was ordered to receive etiquette instruction from the shogun's protocol officer, Kira Yoshinaka, for an upcoming reception of Imperial envoys. Enraged by a perceived insult from Kira, Asano drew his sword inside the shogunal palace — an offense that resulted in his death by seppuku (ritual suicide by the sword) and the dissolution of his domain.
All his retainers lost their posts and, two years later, under the leadership of Yoshio Oishi (often referred to by his title, Oishi Kuranosuke), 47 of these ronin (masterless samurai) staged an attack on Kira's mansion in Edo (old Tokyo), beheaded Kira and, having accomplished their revenge, gave themselves up to the authorities and committed seppuku themselves.