On March 14,1704,the feudal lord of the Ako clan,Asano Takuminokami,slashed down Kira Kouzukenosuke with a sword in the Pine Corridor of the Edo(Tokyo)Castel.
As a samurai would rather die than be disgraced at that time,he had to fight a duel with the person who disgraced him,but both parties to arguments were considered to be at fault and usually punished.
However,the shogun at the time,Tokugawa Tsunayoshi,sentenced Lord Asano to commit seppuku(ritual suicide or harakiri)on that day.
On the other hand,he declared Lord Kira not guilty and even more amazingly praised him for his "proper"behavior.
One year later,on December 14,the 47 ronin led by Oishi Kuranosuke stormed Kira's mansion and avenged their master,and then they were also sentenced to commit seppuku by order of the Shogunate.
They sacrificed their own lives out of loyalty to their lord and corrected the misjudgment of the Shogunate.
This action has been praised and admired by people as a paragon of the samurai spirit for 300 years and these warriors are known as "Ako Gishi"(Loyal samurai)all over the country.