I think I get what you are going for. So, assuming the last bodypart is temporary, then I'd start wtih feet, obvious. Best way to break the Kitsune into their new fate as a permanent resident of the shark. Getting them sweatlogged and thoroughly battered under heavy steps, narrowly avoiding being swallowed by Wendi. From there, I'd work them up onto my next bodypart of choice. Corina's loins. Might as well have it an introduction of spelunking into the shark. Jun will still bet battered of course, both by my quivering walls as well as Corina desperately trying to sate her now endless horniness with every toy she owns. All while Jun is drunk on the scent of the shark's pheromones. But of course, as I said, this is an introduction. The conclusion would be the shark's digestive track. An eldrtich creature deserves a hellish place to inhabit, and what could be more hellish than a positively overactive stomach of a shark that somehow never digests her even as I compel my owner to eat more and more to fill me...despite oddly not affecting her figure at all. Perfect to keep a kitsune locked away from the world in, no matter how they pound on my walls or call for my owner's attention. At least they'll have plenty to eat and drink...even if it was technically consumed already, ehehehe...
Hope that answers your question!