We all have skeletons in our closets, but what is literally contained within Nadeko's? Kaiki now knows the answer to this, but for now we'll have to leave that to our collective imagination.
For now though there's a more pressing issue for Kaiki, as returning to his hotel room he finds a hand-written note telling him to, quite simply, "stay out of it". Who could have penned such a message, and why would they want to? Having already been warned off, and agreed a payment with, Gaen it seems highly unlikely that she'd do anything like this, which leaves Kaiki to turn to Senjougahara to see if she has any ideas. The answer, in short, is no - leaving a note isn't Araragi's style if he were to find out about her plot, and nobody else she knows would interfere.
Written warnings or not, Kaiki still has no intention of giving up on his plan to deceive Sengoku, although given some comments from Senjougahara he does make some alterations to the minutiae of this plot, including visiting her a little less frequently and changing up his usual monetary offerings while also bringing her some sake. Having completed this latest shrine visit however, Kaiki encounters an unexpected individual in the form of Hanekawa, who seems to be in town almost solely to talk with him despite having no questions for him and seeming to know everything about what's going on. So what, exactly, is Tsubasa up to? That's a question left hanging as we head towards the end of this series.
As per a lot of Monogatari Second Season, this final story arc for the series is proving to be something of a slow burner, moving along at a deliberate pace but sprinkled with just enough moments to either entertain or hold the viewer's attention. Certainly, Hanekawa's appearance on the scene has added a new dimension to the story, while the information floating around that we don't know seems likely to provide further big moments over the final couple of episodes of the series.