Kageki

is the younger twin brother of Katazu, the husband of an unnamed woman, and the father an unnamed newborn.

Background
At some point of his life, Kageki married his future wife, and later, the couple had a son.

Kageki had loaned money to Shikazo one time and after his son's birth, 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 with his wife and son, went into hiding, while his twin brother, Katazu, took his identity and got the attention of his pursuers.