The Shadow over Nishinomiya - Author's notesAuthor's notes
TSON is my most misunderstood story, so I thought I'd take a few words to try and explain the mystery. The first clue is that there is a third source that is co-equal with Lovecraft and Tanigawa, and that is Japanese mythology. In a lot of ways TSON can be seen as the evil twin of Eclipse, and I certainly had that in mind when writing both series.
This then explains the one critical fact that was obvious to me, but seemed to slip past every reader. It's my big failing and I guess I have to try harder next time and be half as clever about things. Kyon is Urashima Tarō, Japan's Rip Van Winkle. He is also Ryūjin, the dragon of the sea.
This means that Yuki must be Otohime, of course. I may have been a little heavy handed with the allusions to the turtle-like Kappa, but I didn't want to leave a blinking sign pointed towards Japanese Mermaids, which this version of the Deep Ones are closest to.
I trust that everybody got the Dan Brown references, so I shan't go into that.
Both the mermaids and the cultists use magic by invoking the powers of the two gods. Unfortunately for humanity, the gods are evil. In DnD terms Ryūjin would be Lawful Evil, Hydra would be Chaotic Evil, and the Mermaids are generally Neutral Evil. The little bit about seducing and consuming mortal men keeps them off Santa's nice list I suppose. Also they try to balance between their two patrons, without getting too caught in the crossfire.
Ryūjin is a literal sex god. Nobody but Hydra can tell if he's innately that way or if she just designed humanity (and the Kappa) to react to him this way. I tried to put clues in like the Nun's reaction, but I guess I could have done a bit more on this. I don't go in depth on why he's hidden away his powers and memories, as it doesn't matter for this story. Whatever his problem is, he resolves it.
Mermaid society is very family oriented. This is their neutral balance between a lawful devotion to their great cause or a selfish all for oneself chaotic outlook. By family I mean mother to great to the hundreds grandmothers. Fathers are of course only useful for adopting the look of the locals (for the first hundred years of a daughter's life) and only worth mentioning if the father is Ryūjin himself. Every Kappa can trace her parentage back to him through some living female ancestor, but they're careful not to dip back into that gene pool too often, for fear of attracting Hydra's jealousy.
Hydra herself usually takes the form of mass hysteria, and so everybody is amazed that she's wedged into a single human girl who even seems slightly sane. The one thing Hydra adores is novelty, which is why the rest of the Kappa are so relieved that her current pet is the despised outcast Yuki. This way they're not "it".
I guess I could have done a better job with Yuki's motives. Yuki is tired of being on the run and finds herself intensely attracted to Kyon. This along with his immunity to (well his own) magic clues her in as to his identity. I guess I should have made more of a point of her rationalizing flirting with this human boy before she realizes that hooking up with him is not just the best possible option, but that turning down his advances is basically physically impossible. The books she's been reading for the past half a century have clued her into more of the secrets of her race than even her mother knew.
And yes the espers are more "Call of Cthulhu", but that's just general mythod by now.