"Can you even do that?" Hazō demanded, feeling the ground metaphorically shift beneath his feet. "Leave a clan of your own free will?"
"It is an option virtually never exercised," Keiko said, "but yes. In both Mist and Leaf, the Kage foresaw the benefits of allowing it from the beginning, as should a clan engage in treason or other unpatriotic activity, this provides a mechanism for loyal ninja to abandon it and come under the Kage's exclusive authority."
"But then," Hazō objected, "how could punishments like execution work, if you could just leave the clan to avoid them? Uh, not that I'm saying I'd ever execute you. Please stop looking at me like that."
"That concern, too, is accounted for in law, although in Leaf it took the more pragmatic Second Hokage to patch the holes in the legislation. A sentence severe enough to be worth fleeing from, such as execution, must be countersigned by the Hokage to begin with. Then, even should the criminal leave the clan, the Hokage will not obstruct enforcement of a punishment he has already sanctioned."