Since their job was disliked as it was so-called a dirty job, they formally employed a new person when his predecessor left his office although it was substantially hereditary.
いわゆる汚れ仕事として嫌われたために、実質的には世襲ではあったものの、形式的には代替わりの際には新規召抱えの体裁を踏んだ。