Sanada Nobuyuk is Yukimura's older brother. He joined the Tokugawa Clan at Battle of Sekigahara, seeming to betray his brother, which generated much animosity between the siblings. He and Yukimura fight at the Shogun Tournament, and it is later revealed that during the fight he was actually trying to teach Yukimura a lesson. Nobuyuki never betrayed the family as Yukimura thought; he joined the other side so that no matter who becomes the Shogun, the Sanada Clan would be on the winning side and survive.

Since Nobuyuki and Yukimura both give their ages as thirty-seven and appear virtually identical, they may be twins.