Sengakuji is a well-known temple in Tokyo for the "Ako roshi" or 47 royal retainers of Ako. 47 retainers avenged their feudal load, Asano in Ako in the early 18th Century. This avenge story "Chushin gura" was based on this incident and have been played in Kabuki and TV drama.
In the precincts of Sengakuji, there are 47 graves of royal retainers, the feudal load Asano and his wife's grave. Smoke of incense are never vanished to console their spirits. In 2013, Hollywood created remake movie "47 Ronin" based on Chushin gura story. It's a fantasy and fiction movie so that a part of the story setting are not true. Whatever the truth is, it is a good trigger to have an interest Japanese history.