Shimotsuki Koushirou

Koshiro is the name of Roronoa Zoro's teacher and Kuina's father. He has his own Dojo near where Zoro grew up and he was the one who trained him. He is typically seen in flashbacks. However, recently, in Chapter 440, he makes a brief appearence when another student ofhis asked if he was really Roronoa Zoro's teacher.