You can reach the Kamayama Castle Ruins Tamon Turret in about a 10-minute walk from Kamayama Station, and along the way, you'll find the Ishii Brothers' Revenge Site Monument.
It's a small area, but there's a little plaza there with benches.
This monument marks the spot where the Ishii brothers, whose father and elder brother were killed, avenged them after 29 years.
As a side note, it might be hard to imagine nowadays, but in the Edo period, if you reported the murder of a family member, you could get official permission to seek revenge. However, the success rate was said to be low.

You can reach the Kamayama Castle Ruins Tamon Turret in about a 10-minute walk from Kamayama Station, and along the way, you'll find the Ishii Brothers' Revenge Site Monument.
It's a small area, but there's a little plaza there with benches.
This monument marks the spot where the Ishii brothers, whose father and elder brother were killed, avenged them after 29 years.
As a side note, it might be hard to imagine nowadays, but in the Edo period, if you reported the murder of a family member, you could get official permission to seek revenge. However, the success rate was said to be low.