What metaphors are used in Chushingura, the Treasury of Loyal Retainers: A Puppet Play by Takeda Izumo?

Yuranosuke's slaying of Kudayu is a threshold moment, whereby the true destroys the false. The sword in this case is a metaphor for Yuranosuke himself. He is tarnished and neglected, but Yuranosuke, like his sword, still holds an edge.