I have a very simple cover story for Junkojuro in mind. Whenever he is in plain sight, he acts as a lowly groundskeeper. He can change his appearance, so as the years go on he makes himself look older and older, and ever fifty or so years he appears as the "new" groundskeeper, the "son" of the previous one. If he wants to request an audience, he would simply disguise it as a matter of environmental hazards, be it wild animal attacks or a potential cave-in in one of the mines. If he wants to convince somebody of his true form, he could simply transform into his full fox form before them, surely enough to convince any skeptic. So, Junkojuro probably wants to keep up this cover until he is certain that the young lord is not the type to execute Youkai on the spot. In the meantime, the groundskeeper "family" has a spiritual lineage, and he can still offer spiritual council on the grounds of family traditions. Perhaps he even offered meditation techniques to Takeshi.