Any art survives by the hard work and perseverance of its students and teachers, but what makes a ryu a true koryu is its connection to the past. Unlike in sports, a practitioner cannot be satisfied with skill only. Each must be a link in the chain from one generation to the next. This is especially true for the headmaster. While the responsibility of a student is to eventually become a teacher and help raise the next generation, a headmaster bears the weight of defining the generation itself.
We can easily trace our history to the foundations of the ryu in the 16th century. For generations, the Edo Yagyu Shinkage Ryu was passed on by family lineage, but when no direct descendant was available to inherit the ryu, we transitioned to the teacher-student succession system used today. The current head is the 18th generation, Paul Manogue, who studied directly under the 17th-generation headmaster, Sono Seiko.