And small schools that keeps isshi soden (transmission of the secrets of an art from father to only one child) even now, do not set up dojo on a large scale and the art has been transmitted in succession only within the family, so that if there is no candidate to succeed the next generation, it can easily come to an end while the conditions of the times change.
また現在でも一子相伝とされるような小さな流派では、大々的に道場を構えたりせず一族だけで伝承されてきているため、時代状況の移り変わりの中で、次の世代に継ぐべき人間がいなければ容易に途絶えてしまう。