Yoshitsugu Ōtani

Yoshitsugu Otani (大谷 吉継) is Mitsunari's loyal friend who agreed to help him at Sekigahara. Though he was stricken by leprosy by the time the battle begins, he carries out his promise until his defeat. Historically, he was too frail to move by his own strength but this isn't true for his game appearances.

Kessen
In Kessen, Yoshitsugu is a low-key man who appears for the Western Army. He is dressed in white attire and has a mask to cover the lower part of his face. He calmly asks his comrades to understand his friend's brash nature. In battle, Yoshitsugu leads archery or firearms unit with a small battalion of footmen to protect his men. He is one of the better support units at Sekigahara. If the Toyotomi army consecutively wins their battles, Yoshitsugu lives to see Ieyasu's end. Losing at any other part in the game will result in his death.

Saihai no Yukue
He is Mitsunari's best friend in Saihai no Yukue. He lost one of his eyes to his illness and was ready to die. However, Mitsunari gave him the strength to live and he is willing to use the remainder of his life for his friend.

Quotes

 * "Lord Otani, what is it that inspires you to have such faith in the man?"
 * "Mitsunari and I have bonds built of time."
 * "Out of obligation?!"
 * Yoshihiro and Otani before Sekigahara; Kessen