- Name : Byakuya Matou
- Name in Japanese : 間桐鶴野 (まとう びゃくや, Matou Byakuya)
- Natural Enemy：Kariya Matou
- CV：Katsumi Toriumi
Family Tree
- Father：Zouken Matou
- Brother：Kariya Matou
- Son：Shinji Matou
- Adopted Daughter：Sakura Matou
When he was young he was passed over as heir to the family due to possessing very few, if any, magic circuits. His younger brother Kariya would have become head of the Matou in his place had he not rejected the path of the magus.
In later years he would meet a woman with an "inheritor" sorcery trait and marry, resulting over all in the birth of his son, Matou Shinji. Unfortunately, he was uncapable of sorcery, making Byakuya even more of a disgrace to his family for not producing a worthy heir. This would eventually result in Zouken adopting Sakura Tohsaka as the new heir to the family.
When the 4th Grail War starts, he sends Shinji to study abroad and trains Sakura at the worms storage alongside Zouken. When Kariya returns to the Matou house to save Sakura, Byakuya does not take it well, because he believes that because of Kariya leaving the Matou house 10 years ago, he had to endure the cursed destiny of the family and that he has returned for a selfish reason. In his depression and feeling useless for not being able to do anything, Byakuya becomes a depressed alcohlic who blames Kariya and Sakura for his misery.
After Irisviel was kidnapped by Kariya and Berserker, disguised as Rider; Kiritsugu goes to the Matou house, when he confronts a drunk Byakuya. Believing that he knows what happened to Irisviel, Kiritsugu shoots his hand and leg, but after a short struggle Byakuya declares that he has no idea where is Irisviel and that Kariya was last seen with Kirei Kotomine.
Byakuya survives the 4th Grail War and together with Zouken continues to train Sakura at the worms storage. When Shinji returns to the Matou house, Byakuya tries to protect his innocence and keep the awful truths of his work away from him. However one day Shinji accidentally entered to the worms storage in which Sakura was being infested by the worms. Byakuya did not take it well and started acting distant and defiant towards his son and started spending more time with Sakura, since he no longer needed to hide anything from him.
He died three years before the 5th Grail War, leaving Shinji completely alone, because Zouken was only focused on Sakura.
