Kira Kozukenosuke Yoshihisa was one of Koke Samurai clan that rehired by Tokugawa Ieyasu because of the their important family line. Only Koke could be the officer of service coordinating ceremonies of Shogun and Imperial courts. Kira had 4200 Koku of land in Mikawa.
The house of Kira was used to be 8400 square meters. Today, it remains only one 86th of original size.
At the night of December 14, 1702, 47 Ako Ronin broke into this house and killed Kira. This terrorism was known for the story of Chushingura. There is a well that was used for washing Kira's head.
Kira Kozukenosuke Yoshihisa (吉良上野介義央)
He was born as the first son of Koke Kira Yoshifuyu. Kira clan is the descendant of Ashikaga clan, the family line of Genji, and his mother side is Imagawa that is also very high rank of family line in Japan.
Kira is known as the bad guy because of the story of Chushingura. However, he was known as decent lord in his land Mikawa. He built a huge bank for flood control with his own money, made many new paddy fields and created a salt industry. Because of his great policy, people loved him so much. He loved to ride a red horse and patrol his own land. The bank he built is still exist today, and it is called a Golden bank.
He was also excellent officer to coordinate the ritual reception and ceremony to service the imperial family. His career started when he was 13 years old and never disappointed Shogun Ietsuna, and Tsunayoshi.
The story of Chushingura is considered as the honorable samurai story. However, Kira is actually the victim of the terrorism. The biggest mistake that made Kira bad and most hated guy in the history of Japan is no investigation held. Because Shogun Tsunayoshi was so upset that Asano Takuminokami started fighting in Edo castle and messed up the important ceremony, Tsunayoshi ordered Asano to do Seppuku right away, and he didn't investigate the fact of Asano's action. Therefore, Asano's samurai believed that was the conspiracy of Kira and decided to revenge.
Moreover, the act of 47 Asano's samurai, ronin at this moment, was considered as the justice according to Bushido. So, their terrorism became the story of royal samurai who revenged for their lord. Most of Kira's negative story was probably written after the story of Chushingura became popular.
Chushingura is the fiction story based on the real events. It is not fair to judge Kira's personality just from the story.