Chris Parker
Grandmaster
Tricky. That kind of depends on how vindictive the head of the system is. The way it seems to have been, the students would only stay with an incomplete licence holder (for want of a better term) if they showed remarkable skill, or were moving into their own art (rare, but not unheard of). Often, they would simply up and leave for another teacher. Remember, though, all the ranking, including that of the students, can be revoked if hamon is applied.
To give an example, Hatsumi Sensei in his youth was spending an exorbitant amount each month to learn "a certain kobudo from a teacher". This teacher was Ueno Takashi, and he taught Hatsumi Bokuden Ryu Jujutsu, and Asayama Ichiden Ryu Taijutsu. Hatsumi was such a quick study that he achieved Menkyo Kaiden in Asayama Ichiden within three years. At that point (according to Hatsumi), Ueno Sensei told him that he had no more that he could teach, Hatsumi would need to meet Ueno's teacher. That lead to the meeting of Hatsumi and Takamatsu for the first time. As a result, Takamatsu told Hatsumi that if he wanted to learn from him, he must accept hamon for the systems Ueno had taught him.
As I said, that is Hatsumi's version. There are others, which indicate that Ueno was more a colleague of Takamatsu who shared their martial knowledge together, rather than Ueno being Takamatsu's student. Other versions have Ueno being furious with Hatsumi, and issuing hamon for other reasons, which don't need to be entered into here.
To give an example, Hatsumi Sensei in his youth was spending an exorbitant amount each month to learn "a certain kobudo from a teacher". This teacher was Ueno Takashi, and he taught Hatsumi Bokuden Ryu Jujutsu, and Asayama Ichiden Ryu Taijutsu. Hatsumi was such a quick study that he achieved Menkyo Kaiden in Asayama Ichiden within three years. At that point (according to Hatsumi), Ueno Sensei told him that he had no more that he could teach, Hatsumi would need to meet Ueno's teacher. That lead to the meeting of Hatsumi and Takamatsu for the first time. As a result, Takamatsu told Hatsumi that if he wanted to learn from him, he must accept hamon for the systems Ueno had taught him.
As I said, that is Hatsumi's version. There are others, which indicate that Ueno was more a colleague of Takamatsu who shared their martial knowledge together, rather than Ueno being Takamatsu's student. Other versions have Ueno being furious with Hatsumi, and issuing hamon for other reasons, which don't need to be entered into here.