Kageki

the twin brother of Katazu and the man who accidentally killed Shikazo.

Background
Kageki had loaned money to Shikazo one time and after the birth of his child, he needed the money and asked Shikazo if he can be repaid but he refused. After a small scuffle, Shikazo fell and hit his head on a pickling stone that was hard enough to kill him. Since then, Kageki and his family went into hiding, while his twin brother, Katazu, took his identity and got the attention of his pursuers.