The actor Nakamura Utaemon IV playing the role of Ono no Sadakurô in the 5th act of the drama "Kanadehon Chûshingura" in a print made in 1848 by Utagawa Hirosada

This print, which belongs to a series of twelve prints dedicated to the filial piety associated to the 12 year-marking Chinese zodiacal signs, has the sign of the Boar on it ... and 2007 is the year of the Boar in Japan!

What is the link between the sign of the boar and Ono no Sadakurô?
You'll get the answer by reading the summary of the 5th act of "Kanadehon Chûshingura" [more details]