Soke is a member of the Iga Mountain ninja clan and their Grandmaster, a ninja of high authority who decides who is worthy to learn their arts. He is also the adoptive grandfather of Hanzo - who is in actual fact Kiyoshi Date, Akiko's little brother. It also later revealed that he trained Dragon Eye, unaware of the fact he was evil at heart.
Personality and Appearance
Soke, despite being a ninja, whom all samurai, including Jack, naturally despise as their enemies, seems to be a kind, pure hearted old man. He also thinks that ninja are as innocent as samurai believe themselves to be, stating that "A frog in a well does not know the great sea." He also believes that the samurai knew only of the ninja what they understood and not what was actually true.
He is also shown to have come to terms with dying at his age, saying that he has lived his life and will have no qualms with death. Despite his old, sagely appearance, he is greatly skilled as a ninja, possessing enough skill to be the Grandmaster of his village.
Soke is revealed to be tutoring Hanzo to become the future ninja Grandmaster.
Soke is first introduced when Hanzo, having caught Jack in a trap and knocked him unconscious, goes to find him in profound excitement at having caught a tengu, (a mythical demon bird) which is what he believed Jack to be. Soke instructs Hanzo to free Jack and gives him the choice of either getting captured by the samurai party that is searching for him, dying unguided and lost in the mountains or being guided by Soke and Hanzo to their village. Jack reluctantly agrees to be guided by them and is blindfolded and led by the duo through the Iga Mountains.
At arriving in the village Jack is taken to Soke and Hanzo's house where he stays, not realizing that they are a clan of ninjas. Later, he discovers this and is shocked and confused so Soke knocks him unconsious using a nerve pinch, a part of Dim Mak, a deadly ninja technique. He later talks to Jack who eventually agrees to stay and allows Soke to train him in the way of the Ninja.