Isaza is a minor character who has appeared in three episodes, unlike most minor characters. He is a childhood friend of Ginko and Taku. He is part of a tribe of wanderers who follow the River of Light and determine natural disasters from observing it. The tribe makes money by selling this information to mushishi. Ginko temporarily joined the tribe as a child shortly after losing his memory. Isaza appears in Episode 26 of the first season and Episode 1 and Episode 20 of the second season.
It is implied that he is still alive to the current day.
He is a great fisherman.